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NCERT Solutions for Class 10 Maths Chapter 1

Class 10 Maths NCERT Solutions Chapter 1 Real Numbers

May 20, 2022

Class 10 Maths NCERT Solutions Chapter 1 Real Numbers

Get here Class 10 Maths NCERT Solutions Chapter 1 Real Numbers. These NCERT Solutions for Class 10 of Maths subject includes detailed answers of all the questions in Chapter 1 – Class 10 Real Numbers provided in NCERT Book which is prescribed for class 10 in schools.

Resource: National Council of Educational Research and Training (NCERT) Solutions
Class: 10th Class
Subject: Maths
Chapter: Chapter 1 – Real Numbers

No of Exercises – 4 (Contains 17 Questions)
Class 10 Real Numbers Ex 1.1 – 4 Questions Based on Euclid’s division lemma
Class 10 Real Numbers Ex 1.2 – 7 Questions Based on Fundamental Theorem of Arithmetic, LCM and HCF
Class 10 Real Numbers Ex 1.3 – 3 Questions Based on Rational and Irrational Numbers
Class 10 Real Numbers Ex 1.4 – 3 Questions Based in which you have to expand fractions into decimals and write decimals in their fraction form.

Real Numbers Class 10 Ex 1.1

Question 1
Use Euclid’s division algorithm to find the HCF of :
(i) 135 and 225 (ii) 196 and 38220 (iii) 867 and 255
Solution:
(i) Given numbers are 135 and 225.
On applying Euclid’s division algorithm, we have
225 = 135 x 1 + 90
Since the remainder 90 ≠ 0, so again we apply Euclid’s division algorithm to 135 and 90, to get
135 = 90 x 1 + 45
Since the remainder 45 ≠ 0, so again we apply Euclid’s division algorithm to 90 and 45, to get
90 = 45 x 2 + 0
The remainder has now become zero, so we stop.
∵ At the last stage, the divisor is 45
∴ The HCF of 135 and 225 is 45.

Alternatively:
(i) By Euclid’s Division Algorithm, we have
225 = 135 x 1 + 90 135
= 90 x 1 + 45 90
= 45 x 2 + 0
∴ HCF (135, 225) = 45.
(ii) Given numbers are 196 and 38220
On applying Euclid’s division algorithm, we have
38220 = 196 x 195 + 0
Since we get the remainder zero in the first step, so we stop.
∵ At the above stage, the divisor is 196
∴ The HCF of 196 and 38220 is 196.

Alternatively:
(ii) By Euclid’s Division Algorithm, we have
38220 = 196 x 195 + 0
196 = 196 x 1 + 0
∴ HCF (38220, 196) = 196.

(iii) Given numbers are 867 and 255
On applying Euclid’s division algorithm, we have
867 = 255 x 3 + 102
Since the remainder 102 ≠ 0, so again we apply Euclid’s division algorithm to 255 and 102. to get
255 = 102 x 2 + 51
Since the remainder 51 ≠ 0, so again we apply Euclid’s division algorithm to 102 and 51, to get
102 = 51 x 2 + 0
We find the remainder is 0 and the divisor is 51
∴ The HCF of 867 and 255 is 51.
Alternatively:
(iii) 867 and 255
Step 1: Since 867 > 255,
apply Euclid’s division lemma, to a =867 and b=255 to find q and r
such that 867 = 255q + r, 0 ≤ r<255
On dividing 867 by 255 we get quotient as 3 and remainder as 102
i.e 867 = 255 x 3 + 102

Step 2: Since remainder 102 ≠ 0,
we apply the division lemma to a=255 and b= 102 to find whole numbers q and r
such that 255 = 102q + r where 0 ≤ r<102
On dividing 255 by 102 we get quotient as 2 and remainder as 51
i.e 255 = 102 x 2 + 51

Step 3: Again remainder 51 is non zero,
so we apply the division lemma to a=102 and b= 51 to find whole numbers q and r
such that 102 = 51 q + r where 0 r < 51
On dividing 102 by 51 quotient is 2 and remainder is 0
i.e 102 = 51 x 2 + 0
Since the remainder is zero, the divisor at this stage is the HCF
Since the divisor at this stage is 51,therefore, HCF of 867 and 255 is 51.

Concept Insight: To crack such problem remember to apply Euclid’s division Lemma which states that “Given positive integers a and b, there exist unique integers q and r satisfying a = bq + r, where 0 ≤ r < b” in the correct order.
Here, a > b. Euclid’s algorithm works since Dividing ‘a’ by ‘b’, replacing ‘b’ by ‘r’ and ‘a’ by ‘b’ and repeating the process of division till remainder 0 is reached, gives a number which divides a and b exactly.
i.e HCF(a,b) =HCF(b,r)
Note that do not find the HCF using prime factorization in this question when the method is specified and do not skip steps.

Question 2:
Show that any positive odd integer is of the form 6q + 1, or 6q + 3, or 6q + 5, where q is some integer.
Solution:
Let ‘a’ be any positive integer and b = 6.
∴ By Euclid’s division algorithm, we have
a = bq + r, 0 ≤ r ≤ b
a = 6q + r, 0 ≤ r ≤ b [ ∵ b = 6] where q ≥ 0 and r = 0,1, 2, 3, 4,5
Now, ‘a’ may be of the form of 6q, 6q + 1, 6q + 2, 6q + 3, 6q + 4, 6q + 5
If ‘a’ is of the form 6q, 6q + 2, 6q + 4 then ‘a’ is an even.

In above we can see clearly that the numbers of the form 6q, 6q + 2, 6q + 4 are having the factor 2.
∴ The numbers of the form 6q, 6q + 2, 6q + 4 are even.
If ‘a’ is of the form 6q +1,6q +3, 6q + 5 then ‘a’ is an odd.
As if

∵ We know that the number of the form 2k + 1 is odd.
∴ The numbers of the form 6q + 1, 6q + 3, 6q + 5 are odd.
Alternatively:
Let a be any odd positive integer we need to prove that a is of the form 6q + 1 , or 6q + 3 , or 6q + 5 , where q is some integer. Since a is an integer consider b = 6 another integer applying Euclid’s division lemma
we get a = 6q + r for some integer q ≤ 0, and r = 0, 1, 2, 3, 4, 5 since
0 ≤ r < 6.
Therefore, a = 6q or 6q + 1 or 6q + 2 or 6q + 3 or 6q + 4 or 6q + 5
However since a is odd so a cannot take the values 6q, 6q+2 and 6q+4
(since all these are divisible by 2)
Also, 6q + 1 = 2 x 3q + 1 = 2k1 + 1, where k1 is a positive integer
6q + 3 = (6q + 2) + 1 = 2 (3q + 1) + 1 = 2k2 + 1, where k2 is an integer
6q + 5 = (6q + 4) + 1 = 2 (3q + 2) + 1 = 2k3 + 1, where k3 is an integer
Clearly, 6q + 1, 6q + 3, 6q + 5 are of the form 2k + 1, where k is an integer.
Therefore, 6q + 1, 6q + 3, 6q + 5 are odd numbers.
Therefore, any odd integer can be expressed is of the form
6q + 1, or 6q + 3, or 6q + 5 where q is some integer

Concept Insight: In order to solve such problems Euclid’s division lemma is applied to two integers a and b the integer b must be taken in accordance with what is to be proved, for example here the integer b was taken 6 because a must be of the form 6q + 1, 6q + 3, 6q + 5.
Basic definition of even and odd numbers and the fact that addition and, multiplication of integers is always an integer are applicable here.

Question 3:
An army contingent of 616 members is to march behind an army band of 32 members in a parade. The two groups are to march in the same number of columns. What is the maximum number of columns in which they can march?
Solution:
Maximum number of columns = HCF of (616, 32)
For finding the HCF we should apply Euclid’s division algorithm
Given numbers are 616 and 32
On applying Euclid’s division algorithm, we have
616 = 32 x 19 + 8
Since the remainder 8 ≠ 0, so again we apply Euclid’s division algorithm to 32 and 8, to get
32 = 8 x 4 + 0

The remainder has now become zero, so we stop,
∵ At the last stage, the divisor is 8
∴ The HCF of 616 and 32 is 8.
Therefore, the maximum number of columns in which an army contingent of 616 members can march behind an army band of 32 members in a parade is 8.
Alternatively:
Let n be the number of columns such that the value of n be maximum and it must divide both the numbers 616 and 32.
Then, n = HCF (616, 32)
By Euclid’s Division Algorithm, we have:
616 = 32 x 19 + 8 32 = 8 x 4 + 0
∴ HCF (616, 32) = 8
i. e., n = 8
Hence, the maximum number of columns is 8.

Question 4:
Use Euclid’s division lemma to show that the square of any positive integer is either of the form 3m or 3m + 1 for some integer m.
[Hint : Let x be any positive integer then it is of the form 3q, 3q + 1 or 3q + 2. Now square each of these and show that they can be rewritten in the form 3m or 3m + 1.]
Solution:
Let ‘a’ be any positive integer and b = 3.
∴ By Euclid’s division algorithm, we have a = 3q + r, 0 ≤ r < b
a = 3q + r, 0 ≤ r < 3 [ ∵ b = 3] where q ≥ 0 and r = 0,1, 2
∴ a = 3q or 3q + 1 or 3q + 2
Now

Thus, the square of any positive integer is either of the form 3m or 3m + 1.
Alternatively:
Let a be a positive integer, q be the quotient and r be the remainder.
Dividing a by 3 using the Euclid’s Division Lemma,
we have:
a = 3q + r, where 0 ≤ r < 3
Putting r = 0, 1 and 2, we get:
a = 3q
⇒ a² = 9q²
= 3 x 3q²
= 3m (Assuming m = q²)
Then, a = 3q + 1
⇒ a² = (3q + l)² = 9q² + 6q + 1
= 3(3q ² + 2q) + 1
= 3m + 1 (Assuming m = 3q² + 2q)
Next, a = 3q + 2
⇒ a² = (3q + 2)² =9q² + 12q + 4
= 9q² + 12q + 3 + 1
= 3(3q² + 4q + 1) + 1
= 3m + 1. (Assuming m = 3q² + 4q+l)
Therefore, the square of any positive integer (say, a²) is always of the form 3m or 3m + 1.
Hence, proved.

Question 5:
Use Euclid’s division lemma to show that the cube of any positive integer is of the form 9m, 9m + 1 or 9m + 8.
Solution:

Let ‘a’ be any positive integer and b = 3.
∴ By Euclid’s division algorithm, we have a = bq + r,0 ≤ r ≤ b
a = 3q + r,0 ≤ r < 3 [ ∵ b = 3] where q ≥ 0 and r = 0. 1, 2
∴ a = 3q or 3q + 1 or 3q + 2
Now

Thus, the cube of any positive integer is of the form 9m, 9m + 1 or 9m + 8.

Alternatively:

Let a be a positive integer, q be the quotient and r be the remainder.
Dividing a by 3 using the Euclid’s Division Algorithm, we have,
a = 3q + r, where 0 ≤ r < 3
Putting r = 0, 1 and 2, we get:
a = 3q, a = 3q + 1 and a = 3q + 2
If a = 3q, then a³ = 27q³ = 9(3q³) = 9m. (Assuming m = 3q³.)
If a = 3q + 1, then
a³ = (3q + l)³ = 27q³ + 9q(3q + 1) + 1 = 9(3q³ + 3q² + q) + 1 = 9m + 1, (Assuming m = 3q³ + 3q² + q)
If a = 3q + 2, then a³ = (3q + 2)³= 27q³ + 18q(3q + 2) + (2)³= 9(3q³ + 6q² + 4q) + 8
= 9m + 8, (Assuming m – 3q³ + 6q² + 4q)
Hence, a³ is of the form 9m, 9m + 1 or 9m + 8.

Real Numbers Class 10 Ex 1.2

Question 1:
Express each number as a product of its prime factors:
(i) 140 (ii) 156 (iii) 3825 (iv) 5005 (v) 7429
Solution:

Alternatively:

Alternatively:

Alternatively:

Alternatively:

Alternatively:

Question 2:
Find the LCM and HCF of the following pairs of integers and verify that LCM × HCF = product of the two numbers.
(i) 26 and 91 (ii) 510 and 92 (iii) 336 and 54
Solution:

Alternatively:

Alternatively:

Alternatively:

Question 3:
Find the LCM and HCF of the following integers by applying the prime factorisation method.
(i) 12, 15 and 21 (ii) 17, 23 and 29 (iii) 8, 9 and 25
Solution:
(i) 12, 15 and 21
Method 1:

Alternatively:

Alternatively:

Question 4:
Given that HCF (306, 657) = 9, find LCM (306, 657).
Solution:
Given that HCF (306, 657) = 9
We know that LCM x HCF = Product of two numbers

Alternatively:

Question 5:
Check whether 6ⁿcan end with the digit 0 for any natural number n.
Solution:
Since prime factorisation of 6ⁿ is given by 6ⁿ= (2 x 3)ⁿ = 2ⁿ x 3ⁿ
Prime factorisation of 6ⁿ contains only prime numbers 2 and 3.
6ⁿmay end with the digit 0 for some ‘n’ if 5 must be in its prime factorisation which is not present.
So, there is no natural number VT for which 6ⁿ ends with the digit zero.
Alternatively:

Question 6:
Explain why 7 × 11 × 13 + 13 and 7 × 6 × 5 × 4 × 3 × 2 × 1 + 5 are composite numbers.
Solution:
Method 1:

Both N₁ and N₂ are expressed as a product of primes. Therefore, both are composite numbers.
Alternatively:

Question 7:
There is a circular path around a sports field. Sonia takes 18 minutes to drive one round of the field, while Ravi takes 12 minutes for the same. Suppose they both start at the same point and at the same time, and go in the same direction. After how many minutes will they meet again at the starting point?
Solution:
Method 1:

By taking LCM of time taken (in minutes) by Sonia and Ravi, we can get the actual number of minutes after which they meet again at the starting point after both start at same point and of the same time, and go in the same direction.

Therefore, both Sonia and Ravi will meet again at the starting point after 36 minutes.

Real Numbers Class 10 Ex 1.3

Question 1.
Prove that √5 is irrational.
Solution:
Let us assume that is rational.
∴ There exists co-prime integers a and b (b ≠ 0) such that
√5 = \(\frac { a }{ b }\) ⇒ √5b= 0
Squaring on both sides, we get
5b²= a²…… (i)
⇒ 5 divides a² ⇒ 5 divides a
So, we can write a = 5c for some integer c.
From (i) and (ii)
5b² = 25c²
⇒ b² = 5c²
⇒ 5 divides b²
⇒ 5 divides b
∴ 5 is a common factor of a and b.
But this contradicts the fact that a and b are co-primes.
This contradiction has arisen because of our incorrect assumption that √5 is rational.
Hence, √5 is irrational.
Alternatively:
Let √5 = \(\frac { p }{ q }\) be a rational number, where p and q are co-primes and q ≠ 0.
Then, √5q = p => 5q²=p²⇒ p² – Sq² … (i)
Since 5 divides p², so it will divide p also.
Let p = 5r
Then p² – 25r ² [Squaring both sides]
⇒ 5q² = 25r² [From(i)]
⇒ q² = 5r²Since 5 divides q², so it will divide q also. Thus, 5 is a common factor of both p and q.
This contradicts our assumption that √5 is rational.
Hence, √5 is irrational. Hence, proved.

Question 2.
Show that 3 + √5 is irrational.
Solution:
Let us assume that 3 + 2√5 is rational.
∴ There exists co-prime integers a and b(b ≠ 0) such that

But this contradicts the fact that √5 is irrational.
This contradiction has arisen because of our incorrect assumption that 3 + 2√5 is rational. Hence, we conclude that 3 + 2√5 is irrational.
Alternatively:
Let 3 + 2√5 = \(\frac { p }{ q }\) be a rational number, where p and q are co-prime and q ≠ 0.
Then, 2√5 = \(\frac { p }{ q }\) – 3 = \(\frac { p – 3q }{ q }\)
⇒ √5 = \(\frac { p – 3q }{ 2q }\)
since \(\frac { p – 3q }{ 2q }\) is a rational number,
therefore, √5 is a rational number. But, it is a contradiction.
Hence, 3 + √5 is irrational. Hence, proved.

Question 3.
Prove that the following are irrational.

Solution:

Alternatively:
(i) Let \(\frac { 1 }{ \sqrt { 2 } }\) = \(\frac { p }{ q }\) be a rational number,
where p and q are co-prime and q ≠ 0.
Then, √2 = \(\frac { q }{ p }\)
Since \(\frac { q }{ p }\) is rational, therefore, √2 is rational.
But, it is a contradiction that √2 is rational, rather it is irrational.
Hence, \(\frac { 1 }{ \sqrt { 2 } }\) is irrational.
Hence, proved.

Alternatively:
(ii) Let 7√5 = \(\frac { p }{ q }\) be a rational number, where p, q are co-primes and q ≠ 0.
Then, √5 = \(\frac { p }{ 7q }\)
Since \(\frac { p }{ 7q }\) is rational therefore, √5 is rational.
But, it is a contradiction that √5 is rational rather it is irrational.
Hence, 7√5 s is irrational.
Hence proved.

Alternatively:
(iii) Let 6 + √2 = \(\frac { p }{ q }\) be a rational number, where p, q are co-primes and q ≠ 0.
Then, √2 = \(\frac { p }{ q }\) – 6 = \(\frac { p – 6q }{ q }\)
Since \(\frac { p – 6q }{ q }\) is rational therefore, √2 is rational.
But, it is a contradiction that √2 is rational, rather it is irrational.
Hence, 6 + √2 is irrational.

Real Numbers Class 10 Ex 1.4

Question 1:
Without actually performing the long division, state whether the following rational numbers will have a terminating decimal expansion or non-terminating repeating decimal expansion:

Solution:

Alternatively:

Alternatively:

Alternatively:

Alternatively:

Alternatively:

Alternatively:

(vii)

Alternatively:

(Viii)

Alternatively:

(ix)

Alternatively:

(x)

Alternatively:

Question 2.
Write down the decimal expansions of those rational numbers in the question 1, which have terminating decimal expansions.
Solution:

Alternatively:

Question 3:
The following real numbers have decimal expansions as given below. In each case, decide whether they are rational or not. If they are rational and of the form \(\frac { p }{ q }\), what can you say about the prime factors of q ?
(i) 43. 123456789
(ii) 0.120120012000120000…
(iii) 43. \(\overline { 123456789 }\)
Solution:
(i) 43.123456789
Since the decimal expansion terminates,so the given real number is rational and therefore of the form \(\frac { p }{ q }\)

Here, q = 29 x 59, So prime factorisation of q is of the form 2ⁿ x 5^m.
Alternatively:
(i) 43.123456789

Here, the denominator is of the form 2^m5ⁿ.
Hence, the number is a rational number, specifically a terminating decimal.
(ii) 0.120120012000120000…
Since the decimal expansion is neither terminating nor non-terminating repeating, therefore the given real number is not rational.
Alternatively:
(ii) Since the given decimal number is non terminating non-repeating, it is not rational

(iii) 43. \(\overline { 123456789 }\)
Since the decimal expansion is non-terminating repeating, therefore the given real number is rational and therefore of the form \(\frac { p }{ q }\)
Let x = 43. \(\overline { 123456789 }\) = 43.123456789123456789… ….(i)
Multiply both sides of (i) by 1000000000, we get

Alternatively:
(iii) Since the given decimal number is nonterminating repeating, it is rational, but the denominator is not of the form 2^m5ⁿ.

Class 10 Real Numbers Summary

We have studied the following points:
1. Euclid’s Division Lemma: Given positive integers a and b, there exist whole numbers q and r satisfying a = bq + r where 0 = r = b.
2. Euclid’s Division Algorithm: According to this, which is based on Euclid’s division lemma, the HCF of any two positive integers a and b with a > b is obtained as follows:
Step 1 Apply the division lemma to find q and r where a = bq + r, O = r < b.
Step 2 If r = 0, the HCF is b . If r? 0 apply Euclid Lemma to b and r
Step 3 Continue the process until the remainder is zero. The divisor at this stage will be HCF (a, b). Also HCF (a, b) = HCF (b, r)
3. The Fundamental Theorem of Arithmetic: Every composite number can be expressed (factorized) as a product of primes and this factorization is unique, apart from the order in which the prime factors occur.

4. If p is a prime and p divides a², then p divides a also, where a is a positive integer.

5. If x is any rational number whose decimal expansion terminates, then we can express x in the form p/q, where p and q are coprime, and the prime factorisation of q is of the form 2^m 5ⁿ where m, n are non-negative integers.

6. Let x = p/q be a rational number, such that the prime factorisation of q is of the form 2^m 5ⁿ where m, n are non-negative integers, then x has a decimal expansion which terminates

7. Let x = p/q be a rational number, such that the prime factorisation of q is not of the form – 2^m 5ⁿ, where m, n are non-negative integers, then x has a decimal expansion which is non-terminating repeating (recurring)

8. To Prove √3 Rational Number.

Class 10 Maths Real numbers Mind Map

Euclid’s Division Lemma

For given any two positive integers a and b, there exist unique integers q and r satisfying
a = bq + r, 0 ≤ r < b
Lemma: A lemma is a proven statement used for proving another statement.

Euclid’s Division Algorithm

Euclid’s division algorithm is a technique to compute the Highest Common Factor (HCF) of two given positive integers. To get HCF of two positive integers c and d, c > d following steps are to be followed:

(i) Apply Euclid’s division lemma to c and d to get whole numbers q and r such that
c = dq + r, 0 ≤ r < d.
(ii) If r = 0, then d is HCF of c and d. If r ≠ 0. apply division lemma to d and r.
(iii) Continue the process till the remainder is zero. The divisor at this stage will be the required HCF.

Note:
(i) Euclid’s division lemma and algorithm are so closely interlinked that people often call former as the division algorithm also.
(ii) Euclid’s division algorithm is stated for only +ve integers but it can be extended for all integers except zero.

Fundamental Theorem of Arithmetic

Every composite number can be expressed (factorised) as a product of primes, and this factorisation is unique, apart from the order in which the prime factors occur.
The prime factorisation of a natural number is unique, except for the order of its factors. In general, given a composite number x, we factorise it as
x = P₁P₂P₃…… p_n, where p₁, p₂, p₃……. ,p_n are primes and written in ascending order, i.e.,
p₁ ≤ p₂ ≤ p₃……p_n. If we combine the same primes, we will get powers of primes.
For Example:

So, in each of the cases prime factors of 156 is 2 × 2 × 3 × 13
Hence, we can conclude that the prime factorisation of a number is unique.
Note:
(i) For two positive integers a, b
HCF (a, b) × LCM (a, b) = a × b
(ii) If p is a prime number and it divides a², then p also, divides a where ‘a’ is the positive integer.

HCF and LCM of Three Numbers

Note:
For three positive integers a, b and c
HCF (a, b, c) × LCM (a, b, c) ≠ a × b × c

Irrational Numbers

Number which is not a rational number or whose decimal expansion is non-terminating and non-repeating
Note:
(i) The sum or difference of a rational and an irrational number is irrational, e.g.,
2 + √2 is irrational,
2 – √3 is irrational.
(ii) The product and quotient of a non-zero rational and irrational number is irrational, e.g.,
5 × √2 is irrational
\(\frac{\sqrt{2}}{3}\) is irrational

Rational Numbers and Their Decimal Expansion

(i) If denominator of a rational number is of the form 2ⁿ 5^m, where n, m are non-negative integers then x has decimal expansion which terminates.
(ii) If decimal expansion of rational number terminates then its denominator has prime factorisation of the form 2ⁿ 5^m, where n, m are non-negative integers.
(iii) If denominator of a rational number is not of the form 2ⁿ 5^m, where n and m are non-negative integers then the rational number has decimal expansion which is non-terminating repeating.
Thus we conclude that the decimal expansion of every rational number is either terminating or non-terminating repeating.

NCERT Solutions for Class 10 Maths

Lakhmir Singh Biology Class 10 Solutions Multiple Choice Questions (MCQs)

May 20, 2022

S Chand Biology Class 10 Solutions Multiple Choice Questions (MCQs)

Question 1.
In the sketch of the stomatal apparatus given alongside, which one of the following is missing?

(1) Cell membranes of the cells
(2) Cell walls of the cells
(3) Nuclei in the guard cells
(4) Chloroplasts in the guard cells
Answer:
The nuclei in the guard cells is missing from the sketch of the stomatal apparatus given above.
Hence, the correct answer is option 3.

Question 2.
A student focussed the leaf epidermal peel under the low power of microscope but could not see all the parts. He should .
(1) use the coarse adjustment knob again to focus the slide.
(2) use the fine adjustment knob to increase magnification.
(3) focus under high power using coarse adjustment knob.
(4) focus under high power using fine adjustment knob.
Answer:
In order to view all the parts of a leaf epidermal peel, the student should focus it under high power using fine adjustment knob. Cells are microscopic structures which can be clearly observed only under high power. It also enables us to observe various other components of cells.
Hence, the correct answer is option 4.

Question 3.
The temporary mount of the leaf epidermal peel which looked pinkish red under the microscope was .
(1) stained in acetocarmine and mounted in glycerine
(2) stained in iodine and mounted in water
(3) stained in safranin and mounted in glycerine
(4) stained in methylene blue and mounted in water
Answer:
The temporary mount of leaf is stained with safranine and mounted with glycerine.
Safranine is a dye which can be taken up by cells and gives them a pink colour. The cell as well as the background are both transparent and it is difficult to visualise the cells as such. Staining imparts colour to the cells or its components and enhances its contrast and makes it easier to see them under the microscope.
Hence, the correct answer is option 3.

Question 4.
A well stained leaf peel mount when observed under the high power of a microscope shows nuclei in .
(1) only epidermal cells
(2) only guard cells
(3) guard cells and epidermal cells
(4) guard cells, epidermal cells and stoma
Answer:
Only guard cells and epidermal cells will be visible under the high power of a microscope.
Hence, the correct answer is option 3.

Question 5.
Which structure out of I, II, III and IV marked in the given diagram of the epidermal peel of leaf should be labelled as stoma?

(1) I
(2) II
(3) III
(4) IV
Answer:
Stoma/stomatal pore is an opening surrounded by guard cells. Structure III marked in the given diagram represents stoma.
Hence, the correct answer is option 3.

Question 6.
A student had drawn the diagram of stomata in a hurry, as shown alongside. He could not be given full marks as he.

(1) forgot to draw nuclei in guard cells and also to label the diagram.
(2) did not draw nuclei in guard cells and other cells.
(3) should have drawn nuclei and chloroplasts in guard cells and nuclei in all epidermal cells.
(4) did not label the stoma in the correct position.
Answer:
The student could not get full marks for his diagram because he should have drawn nuclei and chloroplasts in guard cells and nuclei in all epidermal cells.
Hence, the correct answer is option 3.

Question 7.
Bottles containing the undermentioned liquids were available in the laboratory. Which liquid did a student use for putting a drop on the slide before placing the coverslip while preparing the temporary mount of leaf epidermal peel?
(1) Water
(2) Safranin
(3) Glycerine
(4) Iodine
Answer:
The student must have put a drop of glycerine on the slide before placing the coverslip on the slide. Glycerine is a viscous liquid which prevents the specimen from drying out and keeps it moist for longer duration. Also glycerine tends to refract light due to its refractive nature. As a result of which, the image appears clearer under the microscope.
Hence, the correct answer is option 3.

Question 8.
To prepare a good temporary mount of the petunia leaf peel showing many stomata, the student has to get the peel from the .
(1) tip of the leaf
(2) upper surface of the leaf
(3) lower surface of the leaf
(4) point of attachement of leaf to its petiole
Answer:
To prepare a good temporary mount, the student should take the peel from the lower surface of the leaf.
Stomata are structures which help in gaseous exchange and are usually scattered on the lower surfaces of leaf.
Hence, the correct answer is option 3.

Question 9.
While preparing a good temporary mount of leaf peel to observe stomata, care should be taken to avoid.
(1) adding glycerine to the slide
(2) using water to wash the slide
(3) having air bubbles in the slide
(4) staining the peel with safranin
Answer:
A good temporary mount of leaf should be free of any air bubbles. These air bubbles lower the viewing resolution. Thus, all precautions should be taken to avoid having air bubbles in the slide.
Hence, the correct answer is option 3.

Question 10.
In the sketch of stomatal apparatus given alongside, the parts I, II, III and IV were labelled differently by four students. The correct labelling is shown in.

(1) (I) guard cells, (II) stoma, (III) starch granule, (IV) nucleus
(2) (I) cytoplasm, (II) nucleus, (III) stoma, (IV) chloroplast
(3) (I) guard cells, (II) starch, (III) nucleus, (IV) stoma
(4) (I) cytoplasm, (II) chloroplast, (III) stoma, (IV) nucleus
Answer:
The correct labelling of the above diagram is –
(I) cytoplasm, (II) nucleus, (III) stoma, (IV) chloroplast
Hence, the correct answer is option 2.

Question 11.
In the slide of an epidermal peel, the parts which appear pink coloured after staining with safranin are .
(1) stomata only
(2) nuclei only
(3) cell membrane and cytoplasm
(4) all parts in the peel
Answer:
Safranin is a stain which stains all the parts of the epidermal peel pink.
Hence, the correct answer is option 4.

Question 12.
Four students, A, B, C and D, make the records given below, for the parts marked X and Y in this diagram.

Student	X	Y
A B C D	Stoma Guard cell Epidermal cell Stoma	Guard cell Stoma Stoma Epidermal cell

The correct record, out of these, is that of student.
(1) A
(2) B
(3) C
(4) D
Answer:
The correct record is made by student A as X represents stoma whereas Y represents guard cells.
Stoma also known as the stomatal pore is an opening which is surrounded by a pair of guard cells.
Guard cells are bean shaped cells which regulate the opening and closing of the stomatal pore.
Hence, the correct answer is option 1.

Question 13.
The steps involved in making a slide of epidermal peel of leaf are given as follows .
I. Pull out a thin peel from the lower surface of the leaf
II. Place a drop of glycerine on the slide
III. Stain the peel in safranin
IV. Place the stained peel on the glycerine
V. Remove the extra stain by washing with water
VI. Place the coverslip over the peel
Which one is the correct sequence of steps to be followed?
(1) I, II, III, IV, V, VI
(2) I, III, V, II, IV, VI
(3) I, III, IV, II, V, VI
(4) I, II, IV, III,V, VI
Answer:
The correct sequence of steps for making a slide of epidermal peel are –
I. Pull out a thin peel from the lower surface of the leaf
III. Stain the peel in safranin
V. Remove the extra stain by washing with water
II. Place a drop of glycerine on the slide
IV. Place the stained peel on the glycerine
VI. Place the coverslip over the peel
I, III, V, II, IV, VI
Hence, the correct answer is option 2.

Question 14.
Given alongside is a sketch of a leaf partially covered with black paper and which is to be used in the experiment to show that light is compulsory for the process of photosynthesis. At the end of the experiment, which one of the leaf parts labelled I, II and III will become blue black when dipped in iodine solution?

(1) I only
(2) II only
(3) I and III
(4) II and III
Answer:
According to the above sketch, parts I and III will become blue black when dipped in iodine. It is because the starch will be synthesized in parts I and III and whereas it will not be synthesized in part II.
Hence, the correct answer is option 3.

Question 15.
Before testing the leaf for starch at the end of the experiment, ‘light is necessary for photosynthesis’, the experimental leaf should be boiled in.
(1) Water
(2) Alcohol
(3) KOH solution
(4) Hydrochloric acid
Answer:
In the above mentioned experiment, the leaf should be boiled with alcohol to remove chlorophyll.
Hence, the correct answer is option 2.

Question 16.
Given below are the steps to be followed for performing ‘starch test’ on a green leaf.
(A) Boil the leaf in alcohol
(B) Boil the leaf in water
(C) Dip the leaf in iodine solution
(D) Wash the leaf in water
Which one of the following sequences should the students follow to get the correct result?
(1) (A), (D), (B), (C)
(2) (D), (A), (B), (C)
(3) (B), (D), (A), (C)
(4) (B), (A), (D), (C)
Answer:
The following sequence should be followed by students to obtain the correct result in starch experiment –
(B) Boil the leaf in water – to break down the cell membrane of leaf cells and making them more permeable to iodine solution.
(A) Boil the leaf in alcohol – to remove the cholorphyll which interferes in test for starch
(D) Wash the leaf in water – to soften it and remove any chlorophyll molecules attacahed to it
(C) Dip the leaf in iodine solution – to check the presence of starch
(B), (A), (D), (C)
Hence, the correct answer is option 4.

Question 17.
The steps necessary for setting up the experiment, ‘To demonstrate that light is necessary for photosynthesis’ are not given here in proper sequence .
I. Keep the potted plant in sunlight for 3 to 4 hours.
II. Keep the potted plant in darkness for about 48 hours.
III. Cover a leaf of the plant with a strip of black paper.
IV. Pluck the leaf and test it for starch.
The correct sequence of steps is .
(1) I, III, IV, II
(2) I, IV, III, II
(3) II, IV, III, I
(4) II, III, I, IV
Answer:
The following sequence should be followed for setting up the experiment “To demonstrate that light is necessary for photosynthesis” –
II. Keep the potted plant in darkness for about 48 hours. – This is done to destarch the leafs so that no starch is present in the beginning of the expriment itself.
III. Cover a leaf of the plant with a strip of black paper. – This is done to prevent the synthesis of starch in that region.
I. Keep the potted plant in sunlight for 3 to 4 hours. – This is done so that photosynthesis can occur and synthesis of starch can take place.
IV. Pluck the leaf and test it for starch. – The leaf is tested for the presence of starch.
II, III, I, IV
Hence, the correct answer is option 4.

Question 18.
On completion of the experiment to demonstrate that ‘Light is necessary for photosynthesis’, four students reported the inference as follows. Identify the correct inference.
(1) Part of the leaf covered with strip can only undergo photosynthesis.
(2) Uncovered part of the leaf cannot synthesise starch
(3) Photosynthesis takes place only in the presence of sunlight
(4) Light is necessary for the synthesis of starch in green plants.
Answer:
The correct inference for the above experiment is light is necessary for the synthesis of starch in green plants. Green plants cannot synthesise starch in the absence of light. Important requirement for photosynthesis to occur in plants is chlorophyll, sunlight and water.
Hence, the correct answer is option 4.

Question 19.
In the experiment to show that light is necessary for photosynthesis, the plucked leaf is boiled in ethanol and then washed with water. After this, it is tested for the presence of a carbohydrate by a chemical which is .
(1) salt solution
(2) sugar solution
(3) iodine solution
(4) starch solution
Answer:
The chemical used for testing the leaf is iodine solution. It is used to test the presence of starch in leafs.
Hence, the correct answer is option 3.

Question 20.
In the experiment to show that light is necessary for photosynthesis, some of the steps of the experiment deal with the following activities.
I. Starch reacts with iodine and gives blue-black colour
II. Chlorophyll is dissolved in ethanol
III. Hot water makes leaf tissue soft
The correct sequence of these steps is .
(1) I–II–III
(2) II–III–I
(3) III–II–I
(4) I–III–II
Answer:
The correct sequence of steps for the above mentioned experiment is II – III – I.
II. Chlorophyll is dissolved in ethanol
III. Hot water makes leaf tissue soft
I. Starch reacts with iodine and gives blue-black colour
Hence, the correct answer is option 2.

Question 21.
A portion of each of four destarched leaves of a plant was covered with paper strips of various kinds. The plant was exposed to sunlight for 5 hours. Thereafter, the strips were removed and the leaves tested for starch in the covered portion. Which one out of the four leaves gave the starch test in the covered portion?
(1) that covered with black paper strip
(2) that covered with green paper strip
(3) that covered with white paper strip
(4) that covered with transparent paper strip
Answer:
The leaf covered with transparent paper strip will give a positive starch test as the light will be easily absorbed by leafs.
Hence, the correct answer is option 4.

Question 22.
In order to destarch the leaves for an experiment to show that sunlight is necessary for photosynthesis, the.
(1) leaves are kept in alcohol and boiled in a water bath
(2) leaves are soaked in iodine for two hours
(3) plant with the leaves is kept in dark room for 48 hours.
(4) plant with the leaves is exposed to light of a lamp, a night before the experiment
Answer:
In order to destarch the leaves for the experiment to show that sunlight is necessary for photosynthesis, the plants with leaves is kept in dark room for 48 hours.
Hence, the correct answer is option 3.

Question 23.
Which one of the following is the correct combination of relevant materials required for setting up an experiment to show that light in necessary for photosynthesis?
(1) destarched leaves, strips of black paper, starch solution, and iodine crystals
(2) a potted plant, strips of coloured paper, starch solution, iodine and potassium iodide
(3) destarched leaves, strips of black paper, starch solution, and potassium iodide
(4) destarched leaves, strips of black paper, and iodide solution
Answer:
The correct combination of materials for the above mentioned experiment are –
destarched leaves – to check the synthesis of starch
strips of black paper – to cover the leafs
iodine solution – to check the presence of starch
Hence, the correct answer is option 4.

Question 24.
A portion of destarched leaf of a potted plant was covered with a black strip of paper. The plant was then exposed to sunlight for six hours and then tested for starch. It was observed that.
(1) both covered and uncovered parts of leaf turned blue-black
(2) both covered and uncovered parts of leaf turned yellow-brown
(3) only the uncovered part of leaf turned blue-black
(4) only the covered part of leaf turned blue-black
Answer:
In the above case, only the uncovered part of leaf turned blue black. Although the leaf had been destarched earlier, keeping it exposed to sunlight led to the synthesis of starch. But this process would not occur in parts which had been covered.
Hence, the correct answer is option 3.

Question 25.
A star-shaped figure was cut in the black paper strip used for covering the leaf of a destarched plant used for demonstrating that light is necessary for photosynthesis. At the end of the experiment when the leaf was tested for starch with iodine, the star-shaped figure on the leaf was found to be.

(1) colourless
(2) green in colour
(3) brown in colour
(4) blue-black in colour
Answer:
The star shaped figure would be found to be blue black in colour indicating the presence of starch in that area.
Hence, the correct answer is option 4.

Question 26.
In an experiment to test the presence of starch in a leaf, the leaf is boiled in alcohol for a few minutes using a water bath. This is an essential step in the experiment because alcohol.
(1) softens the leaf
(2) disinfects the leaf
(3) allows iodine to enter the leaf
(4) dissolves chlorophyll from leaf
Answer:
Boiling the leaf in alcohol before testing the presence of starch in a leaf is an essential step. It removes the chlorophyll from leaves.
Hence, the correct answer is option 4.

Question 27.
For the experiment ‘Light is necessary for photosynthesis’, the potted plant was first kept in darkness for a day. This is to.
(1) deactivate chloroplasts
(2) destarch leaves
(3) activate chloroplasts
(4) prepare leaves for photosynthesis
Answer:
For the experiment ‘Light is necessary for photosynthesis’, the potted plant was first kept in darkness for a day to destarch the leaves.
Hence, the correct answer is option 4.

Question 28.
When asked to set up an experiment to show that ‘light is necessary for photosynthesis’, a student ran to the school garden and set up the experiment by using a plant growing in the school garden. The experiment failed. His classmates made the following suggestions to get success in the experiment.
Student A . Safranin should be used instead of iodine
Student B . The leaf should not be boiled in alcohol to remove chlorophyll before testing for starch
Student C . Transparent paper should be used instead of black paper strip.
Student D . The leaf should be destarched before starting the experiment
The correct suggestion is given by .
(1) student A
(2) student B
(3) student C
(4) student D
Answer:
The correct suggestion was given by student D. The leaf should be destarched before performing the experiment. The leafs need to be destarched so that we can check during the experiment that starch synthesis occurs or not in the region covered with black strip.
Hence, the correct answer is option 4.

Question 29.
The steps taken for setting up an experiment to demonstrate that ‘light is necessary for photosynthesis’, were as follows .
• A strip of black paper was clipped on the leaf of a potted plant
• The plant was kept in the sun for four hours
• The strip was removed and the leaf was placed in boiling alcohol in water bath
• The leaf was washed and tested for starch
The result was not as expected. Identify the step which had been missed out .
(1) The plant was kept in the dark for 24 hours before starting the experiment
(2) The leaf was boiled in water after placing it in boiling alcohol
(3) The leaf was sprinkled with water before placing it in black paper strip
(4) A transparent strip was used to cover the black paper strip
Answer:
In the above experiment, the step which requires to keep the plant in dark for 24 hrs was missing before starting the experiment.
It is important to keep the plant in dark before starting the experiment so that all the leafs can be destarched.
Hence, the correct answer is option 1.

Question 30.
Out of the following figures, choose the one showing the correct procedure for removing chlorophyll from the leaf in the experiment ‘light is necessary for photosynthesis’.

The correct procedure is .
(1) A
(2) B
(3) C
(4) D
Answer:
The figure in option C shows the correct figure for the experiment ‘light is necessary for photosynthesis’. The correct method of destarching the leafs is by boiling the leaf in ethanol kept in a water bath. Ethanol cannot be directly heated as it is a flammable substance.
Hence, the correct answer is option 3.

Question 31.
A leaf of destarched healthy potted plant was covered by black paper strip as shown in Figure I, and kept in sunlight in the morning. In the evening, it was plucked off and tested for the presence of starch by using iodine solution.

The observation is matched with the Figure No..
(1) II
(2) III
(3) IV
(4) V
Answer:
The observation in figure II correlates with the observation. The covered part shows yellow colour whereas the exposed parts show blue black colour on testing with iodine. Presence of blue black colour indicates the synthesis of starch in that region.
Hence, the correct answer is option 1.

Question 32.
In an experiment to test the presence of starch in a leaf, the plucked leaf is first boiled in water for a few minutes. This is an important step in the experiment because it .
(1) converts glucose made in the leaf into starch
(2) dissolves chlorophyll present in the green leaf
(3) extracts starch to destarch the leaf
(4) makes the leaf more permeable to iodine solution
Answer:
In the above mentioned experiment, the plucked leaf is first boiled in water to extract the starch and destarch the leaf.
Hence, the correct answer is option 3.

Question 33.
Why is some KOH placed in a small test tube in the flask with germinating seeds in the experiment to demonstrate occurrence of respiration in germinating seeds?
(1) To provide oxygen required by the seeds for respiration.
(2) To absorb carbon dioxide and create partial vacuum in the flask.
(3) To absorb water from the seeds to make them dry.
(4) To make the air present in the flask alkaline.
Answer:
KOH is placed in the small tube to absorb carbon dioxide and create partial vacuum in the flask. This absorption of CO₂ by KOH creates partial vacuum in the flask resulting in increase in the water level in the bent tube.
Hence, the correct answer is option 2.

Question 34.
Which one of the following is the correct set of three precautions for setting up the experiment to demonstrate that carbon dioxide is evolved during respiration?
(1) Air tight set up; delivery tube dips in water in beaker; flask has seeds which have just germinated.
(2) Thread holding KOH test tube; air tight flask; delivery tube above surface of water in the beaker.
(3) Germinated seeds under water in the flask; experimental set up not air tight; delivery tube above water level.
(4) Delivery tube touching bottom of water; KOH test tube held by a thick wire; seeds covered by water.
Answer:
The precautions which should be taken –
Air tight set up – an air tight set up is required, so that the CO₂ produced during respiration does not escape out
Delivery tube dips in water in beaker – the delivery tube needs to touch the water, so that the water can rise in the tube when partial vacuum is created in the flask.
Flask has seeds which have just germinated – germinated seeds will produce CO₂ during the experiment which is an important requirement for this experiment.
Hence, the correct answer is option 1.

Question 35.
The experimental set up shown here to demonstrate that ‘CO₂ is given out during respiration’, did not yield expected results because .

(1) the flask was not air tight
(2) there was no KOH in test tube in the flask
(3) the delivery tube was dipped in water
(4) the germinating seeds were not immersed in water
Answer:
The above experiment did not yield the desired results as there was no KOH tube in the flask. KOH absorbs CO₂ and creates partial vacuum in the flask which leads to increase in the water level in the delivery tube. The increase in the water level in the bent tube is an indication that
CO₂ is produced during respiration.
The correct set up is

Hence, the correct answer is option 2.

Question 36.
The following experimental set-ups were kept in the laboratory to show that ‘CO₂ is given out during respiration’

After two hours, students observed that water rises in the delivery tube.
(1) only in set up (A)
(2) only in set up (B)
(3) in both (A) and (B)
(4) neither in set up (A) nor in set up (B)
Answer:
In this experiment, the water will rise only in set up A. In set up A, the flask is made air tight with the help of a cork whereas in set up B, a cotton plug is used. It does not create an air tight condition as a result of which water would not rise in set up B.
Hence, the correct answer is option 1.

Question 37.
In the experiment to show that CO₂is given out during respiration by germinating seeds, the student uses.
(1) Lime water
(2) Alcohol
(3) KOH solution
(4) Iodine solution
Answer:
In the experiment to show that CO₂ is produced during respiration by germinating seeds, KOH solution is used. KOH solution is used to absorb the CO₂ produced during respiration which results in the creation of vacuum in the flask
Hence, the correct answer is option 3.

Question 38.
The most appropriate reason for taking germinating seeds in the experiment to show that carbon dioxide is produced during respiration, is .
(1) germinating seeds create high temperature
(2) germinating seeds are easy to handle
(3) germinating seeds are living things
(4) germinating seeds are in dormant to state
Answer:
The most appropriate reason to take germinating seeds in this experiment is that germinating seeds are living things. Only living things show the process of respiration. Use of seeds for this experiment does not lead to any ethical issues and are also easier to work with as compared to animals.
Hence, the correct answer is option 3.

Question 39.
Before setting up an experiment to show that seeds release carbon dioxide during respiration, the seeds should be.
(1) dried completely
(2) boiled to make them soft
(3) soaked in potassium hydroxide solution
(4) kept moist till they germinate
Answer:
In the above mentioned experiment, the seeds need to be kept moist till they germinate. If the seeds are not kept moist, they would dehydrate and eventually die.
Hence, the correct answer is option 4.

Question 40.
Which of the following precautions are to be taken for a successful run of the experiment to show that carbon dioxide is given out during respiration?
A. Cork should be air-tight
B. Seeds in the flash should be totally dry
C. A small tube with freshly prepared KOH solution should be placed in the flask
D. The end of the delivery tube should be above water level
The correct answer is .
(1) A and B
(2) A and C
(3) A, B and C
(4) A, B and D
Answer:
The precautions to be taken in the above experiment are –
A. Cork should be air-tight so that the carbon dioxide produced during the process does not escape out.
C. A small tube with freshly prepared KOH solution should be placed in the flask so that it can absorb the carbon dioxide produced and create a vacuum in the flask. This vacuum is necessary for the water level to rise in the bent tube.
Hence, the correct answer is option 2.

Question 41.
The chemical required in the experiment to show that carbon dioxide gas is released during respiration is.
(1) potassium bicarbonate
(2) potassium dichromate
(3) potassium permanganate
(4) potassium hydroxide
Answer:
The chemical required in the experiment to show that carbon dioxide gas is released during respiration is potassium hydroxide. Potassium hydroxide absorbs the carbon dioxide produced during the process of respiration and creates a vacuum in the flask.
Hence, the correct answer is option 4.

Question 42.
In the experiment to demonstrate that CO₂ is given out during respiration, what would you observe in the delivery tube dipped in water?
(1) Water level rises in the delivery tube
(2) Water turns milky and rises in the delivery tube
(3) Water turns milky but does not rise in the delivery tube
(4) Water level in the delivery tube remains unchanged
Answer:
In the experiment to demonstrate that CO₂ is given out during respiration, it should be observed that water level rises in the delivery tube.
Hence, the correct answer is option 1.

Question 43.
An experimental set-up to demonstrate respiration in germinating seeds is shown here. It is observed that water from the beaker has not risen into the delivery tube (bent tube). This is because .

(1) the set-up is airtight
(2) the beaker has coloured water
(3) carbon dioxide is not being absorbed
(4) no oxygen is available to seeds for respiration
Answer:
In the above experiment, it is observed that water from the beaker has not risen into the delivery tube which means that carbon dioxide is not being absorbed.
In the small tube, KCl is present instead of KOH which is required for absorbing CO₂ and creating partial vacuum.
Hence, the correct answer is option 3.

Question 44.
In the experiment to show that carbon dioxide is given out during respiration in humans, the student uses .
(1) lime water
(2) alcohol
(3) potassium hydroxide solution
(4) iodine solution
Answer:
In the above mentioned experiment, the student uses lime water which turns milky when CO₂ passes through it.
Hence, the correct answer is option 1.

Question 45.
An experimental set-up is given here to demonstrate that CO₂ is given out during respiration. Four students made the following observations marked as I, II, III and IV.

I. Level of water remained the same in both the beaker and the delivery tube
II. Level of water increased in the delivery tube
III. Level of water reduced in both the beaker and the delivery tube
IV. Water ascends into the delivery tube and back flows into the beaker.
Which one of the above is the correct observation?
(1) I
(2) II
(3) III
(4) IV
Answer:
The correct observation is that the level of water increased in the delivery tube.
Hence, the correct answer is option 2.

Question 46.
The given slides A and B were identified by four students I, II, III and IV as stated below.

Slide A		Slide B
I.	Binary fission in Amoeba	Daughter cells of Amoeba
II.	Budding in yeast	Buds of yeast
III.	Binary fission in Amoeba	Buds of yeast
IV.	Budding in yeast	Daughter cells of Amoeba

Of the above mentioned identification of slides A and B, which one is correct?
(1) I
(2) II
(3) III
(4) IV
Answer:
The observation made by student I is correct as slide A shows binary fission in Amoeba and slide B shows daughter cells of Amoeba.
Hence, the correct answer is option 1.

Question 47.
The correct diagram showing an Amoeba undergoing binary fission is .

(1) I
(2) II
(3) III
(4) IV
Answer:
The correct diagram showing an Amoeba undergoing binary fission is diagram III.
The process of binary fission begins with the division of the nucleus into two, which is then followed by the division of the amoebic body into 2 daughter cells. Each daughter cell contains a nucleus.
Hence, the correct answer is option 3.

Question 48.
The figure given here shows.

(1) Amoeba undergoing binary fission
(2) Yeast undergoing binary fission
(3) Yeast undergoing budding
(4) Amoeba undergoing budding
Answer:
The above figure shows Yeast undergoing budding.
Hence, the correct answer is option 3.

Question 49.
Four stages of binary fission in Amoeba are shown below. The stage at which nuclear fission and cytokinesis are observed is, stage.

(1) I
(2) II
(3) III
(4) IV
Answer:
The stage at which nuclear fission and cytokinesis are observed in Amoeba is stage II.
The process of binary fission begins with the division of the nucleus into two (cytokinesis), which is then followed by the division of the amoebic body into 2 daughter cells. Each daughter cell contains a nucleus.
Hence, the correct answer is option 2.

Question 50.
In the slides showing binary fission in Amoeba and budding in yeast, the correct observations are .
(1) the daughter cells of Amoeba and the bud of yeast are smaller than their respective parental cells
(2) the daughter cells of Amoeba and the bud of yeast are of the same size as their respective parental cells
(3) the daughter cells of Amoeba are bigger than the parent but the bud of yeast is smaller than the parent
(4) the daughter cells of Amoeba are smaller than the parent but the bud of yeast is larger than the parent
Answer:
The correct observations are – the daughter cells of Amoeba and the bud of yeast are smaller than their respective parental cells. Since, in both the cases, the daughter cells are a result of division of the parent cell, their sizes are comparatively smaller to the parent cell.
Hence, the correct answer is option 1.

Question 51.
In the figure of budding in yeast given here, the structures A, B, C and D should be labelled respectively as .

(1) nucleus of bud, bud, yeast, nucleus
(2) dividing nucleus of bud, bud, yeast, nucleus
(3) nucleus of bud, bud, yeast, dividing nucleus of yeast
(4) dividing nucleus of yeast, yeast, bud, nucleus of bud
Answer:
The structures A, B, C and D should be labelled respectively as nucleus of bud, bud, yeast, nucleus.
Hence, the correct answer is option 1.

Question 52.
The diagram given alongside illustrates .

(1) bud formation in yeast
(2) binary fission in amoeba
(3) formation of daughter cells in yeast
(4) formation of pseudopodia in amoeba
Answer:
The diagram shows binary fission in Amoeba.
The process of binary fission begins with the division of the nucleus into two, which is then followed by the division of the amoebic body into 2 daughter cells. Each daughter cell contains a nucleus.
Hence, the correct answer is option 2.

Question 53.
Which stage out of those marked I, II, III and IV is showing the binary fission in Amoeba?

(1) I
(2) II
(3) III
(4) IV
Answer:
Stage IV shows binary fission in Amoeba.
Hence, the correct answer is option 4.

Question 54.
The following figures illustrate the binary fission in Amoeba in an incorrect sequence .

The correct sequence is .
(1) I, III, IV, II
(2) II, III, IV, I
(3) IV, III, II, I
(4) III, IV, II, I
Answer:
The correct sequence of binary fission in amoeba is II, III, IV, I.
The process of binary fission begins with the division of the nucleus into two, which is then followed by the division of the amoebic body into 2 daughter cells. Each daughter cell contains a nucleus.
Hence, the correct answer is option 2.

Question 55.
Which one of the following sketches does not illustrate budding in yeast?

(1) I
(2) II
(3) III
(4) IV
Answer:
Sketch II does not represent budding in Yeast. It represents a stage of binary fission in Amoeba.
Hence, the correct answer is option 2.

Question 56.
Slides A and B show stages of asexual reproduction in two different organisms.

The slides A and B are depicting .
(1) binary fission in both Amoeba and Yeast
(2) budding in both Amoeba and Yeast
(3) binary fission in yeast and budding in Amoeba
(4) binary fission in Amoeba and budding in Yeast
Answer:
Slides A and B represent binary fission in Amoeba and budding in Yeast respectively.
Hence, the correct answer is option 4.

Question 57.
The given slides A and B were identified by four students I, II, III and IV as sated below.

Slide A	Slide B
I. Binary fission in Amoeba II. Budding in Yeast III. Binary fission in Amoeba IV. Budding in Yeast	Daughter cells of Amoeba Buds of Yeast Buds of Yeast Daughter cell in Amoeba

Of the above mentioned identifications of slides A and B, which one is correct?
(1) I
(2) II
(3) III
(4) IV
Answer:
Identification I is correct as slide A shows binary fission in Amoeba and slide B shows daughter cells of Amoeba.
Hence, the correct answer is option 1.

Question 58.
Each of the three beakers A, B and C contained 50 mL of distilled water. A student placed five raisins in each beaker. The raisins for each beaker weighed the same. The beakers were kept at room temperature. The raisins were removed from beaker A after 10 minutes, from beaker B after 20 minutes and from beaker C after one hour. On calculating the percentage of water absorbed by the raisins, it was found that.
(1) maximum absorption of water by raisins was in beaker C
(2) maximum absorption of water by raisins was in beaker B
(3) minimum absorption of water by raisins was in beaker C
(4) absorption of water was equal in raisins of all the three beakers
Answer:
The maximum absorption of water by raisins was in beaker C as they were placed in the beaker for the longest duration.
Hence, the correct answer is option 1.

Question 59.
The following data was obtained on performing an experiment for determining the percentage of water absorbed by raisins.
Mass of water in the beaker = 50 g
Mass of dry raisins = 20 g
Mass of raisins after soaking in water = 30 g
Mass of water left in the beaker after the experiment = 40 g
The percentage of water absorbed by raisins will be.
(1) 10%
(2) 25%
(3) 45%
(4) 50%
Answer:
The percentage of water absorbed is calculated as

Hence, the correct answer is option 4.

Question 60.
At the end of the experiment, ‘to determine the percentage of water absorbed by raisins’, the raisins are wiped just before weighing. This is to ensure that.
(1) hands do not get wet
(2) the raisins lose water before weighing
(3) the weighing scale does not get wet
(4) only water absorbed by raisins is weighed
Answer:
In the above experiment, raisins are wiped just before weighing so that only the water absorbed by raisins is weighed.
Hence, the correct answer is option 4.

Question 61.
A student soaked 5 g of raisins in beaker (A) containing 25 mL of ice-chilled water and another 5 g of raisins in beaker (B) containing 25 mL of tap water at room temperature. After one hour the student observed that.
(1) water absorbed by raisins in beaker (A) was more than that absorbed by raisins of beaker (B).
(2) water absorbed by raisins in beaker (B) was more than that absorbed by raisins of beaker (A).
(3) the amount of water absorbed by the raisins of both beakers (A) and (B) was equal.
(4) no water was absorbed by raisins in either of the beakers (A) and (B).
Answer:
It will be observed that the water absorbed by raisins in beaker (B) was more than that absorbed by raisins of beaker (A). It is because rate of imbibition is directly proportional to the temperature. Higher the temperature of water, higher will be the rate of imbibition of water.
Hence, the correct answer is option 2.

Question 62.
Raisins are soaked in water for determining the percentage of water absorbed by raisins. The formula used by a student for calculating the percentage of water absorbed, is.

Answer:
The correct formula for calculating the percentage of water absorbed, is.
Hence, the correct answer is option 2.

Question 63.
A student soaked 10 g of raisins in 50 mL of distilled water in two beakers A and B each. She maintained beaker A at 25°C and beaker B at 50°C. After an hour, the percentage of water absorbed will be.
(1) the same in both A and B
(2) more in A than in B
(3) more in B than in A
(4) exactly twice in B than in A
Answer:
The percentage of water absorbed will be more in B than in A. It is because rate of imbibition is directly proportional to the temperature. Higher the temperature of water, higher will be the rate of imbibition of water.
Hence, the correct answer is option 3.

Question 64.
A Student dissolved 5 g of sugar in 100 mL of distilled water in beaker A. He dissolved 100 g of sugar in 100 mL of distilled water in beaker B. Then he dropped a few raisins of equal weight in each beaker. After two hours he found the raisins in A swollen and those in B shrunken. The inference drown is that.
(1) sugar concentration of raisins is lower than that of solution A and higher than that solution B.
(2) sugar concentration of raisins is higher that that of solution A and lower that that of solution B.
(3) in B the cell membrane of raisins was damaged resulting in bleaching.
(4) in A the permeability of water of the cell membrane of raisins was enhanced
Answer:
In the first case, the sugar concentration of raisins was less as compared to the solution in the beaker. As a result, water moves into the raisins causing them to swell.
Hence, the correct answer is option 2.

Question 65.
Which of the following set of materials is required to set up an experiment to determine the percentage of water absorbed by raisins?
(1) raisins, breaker of water, filter paper, petri dish, weight box, balance
(2) raisins, petri dish, beaker, filter paper, weight box, balance
(3) raisins, beaker of water, blotting paper, physical balance, weight box
(4) raisins, beaker, blotting paper, petri dish, weight box, balance
Answer:
The following set of materials is required to set up an experiment to determine the percentage of water absorbed by raisins – raisins, beaker of water, blotting paper, physical balance, weight box.
Hence, the correct answer is option 3.

Question 66.
An experiment was set up to determine the percentage of water absorbed by raisins. If the mass of dry raisins was 40 g, and the mass of wet raisins was 45 g, then the percentage of water absorbed would be .

Answer:
Percentage of water absorbed by raisins \(=\frac{W_{2}-W_{1}}{W_{1}} \times 100\)
The percentage of water absorbed in the above case would be \(=\frac{(45-40) g}{40 g} \times 100\)
Hence, the correct answer is option 3.

Question 67.
5 dry raisins were placed in each of the two beakers containing 50 mL of water. After four hours, the raisins were taken out and wiped. For calculating the percentage of water absorbed by raisins, the raisins should have been weighed.
(1) only before placing in water
(2) only after four hours of their being in water
(3) both before and after placing in water
(4) before and at intervals of every hours
Answer:
The formula for calculating the percentage of water absorbed
So, for calculating the percentage of water absorbed by raisins, they should have been weighed both before and after placing in water.
Hence, the correct answer is option 3.

Question 68.
Raisins swell up after being placed in a beaker containing water for some time because .
(1) the concentration of water in the cell sap is higher than the water in the beaker
(2) the concentration of water in the cell sap is lower than the water in the beaker
(3) the concentration of water in the cell sap is the same as that of water in the beaker
(4) water inside the raisins passed out of them when placed in a beaker of water
Answer:
As the concentration of water inside the cell sap is lower, the water from beaker will move inside the cell sap resulting in the swelling of raisins. This process is termed as osmosis.
Hence, the correct answer is option 2.

Question 69.
A group of students performed an experiment to determine the percentage of water absorbed by raisins.The initial weight of raisins is 5 grams and final weight is 8 grams. The percentage of water absorbed will be .
(1) 62.5
(2) 160
(3) 60
(4) 20
Answer:
The percentage of water absorbed will be \(=\frac{\text { Final weight-Initial weight }}{\text { Initial weight }} \times 100\)
\(=\frac{8-5}{5} \times 100=60 \%\)
Hence, the correct answer is option 3.

Question 70.
If the weight of dry raisins is W1 and that of soaked raisins is W2 ,then the correct equation for calculating the percentage of water absorbed by raisins will be .
(1) W1 – W2
(2) W2 – W1
(3) \(\frac{W_{2}-W_{1}}{W_{1}} \times 100\)
(4) \(\frac{W_{1}-W_{2}}{W_{2}} \times 100\)
Answer:
The correct equation for calculating the percentage of water absorbed by raisins will be \(\frac{W_{2}-W_{1}}{W_{1}} \times 100\)
where, W₁ = Initial weight of raisins
W₂ = Final weight of raisins
Hence, the correct answer is option 3.

Question 71.
In the experiment to show that carbon dioxide is produced during respiration by germinating seeds, the alkali solution kept in a small test-tube absorbs.
(1) only O₂ gas
(2) only CO₂ gas
(3) both O₂ and CO₂ gases
(4) neither O₂ nor CO₂ gases
Answer:
In the above mentioned experiment, the alkali (KOH) kept in a small test tube absorbs only CO₂ gas and creates partial vacuum in the flask.
Hence, the correct answer is option 2.

Question 72.
During the preparation of slide, a drop of glycerine is used so that.
(1) material sticks on the slide
(2) bacteria may not attack the material
(3) material may not dry up
(4) visibility of material through the microscope may improve
Answer:
During the preparation of slide, glycerine is used to prevent the drying up of material used as a specimen. Glycerine is a viscous liquid which prevents the specimen from drying out, so that it can be clearly viewed under the microscope.
Hence, the correct answer is option 4.

Question 73.
During the preparation of a temporary mount of leaf peel, the excess glycerine is removed by.
(1) dipping slide in water
(2) a blotting paper
(3) a cotton cloth
(4) tilting the slide
Answer:
The excess of glycerine is removed by using a blotting paper. Excess of glycerine, interferes with observation of the specimen under the microscope.
Hence, the correct answer is option 2.

Question 74.
The apparatus required to perform the experiment to show the evolution of carbon dioxide during respiration includes.
(1) flat-bottom flask, rubber cork , small glass tube, water, KOH solution, delivery tube ,germinating seeds, thread, vaseline, small beaker
(2) round-bottom flask, rubber cork, boiling tube, water, NaOH solution, delivery tube ,dry seeds, thread, vaseline, small beaker
(3) measuring-flask, rubber cork, small glass tube, water, Na₂CO₃ solution, delivery tube, germinating seeds, thread, vaseline, small beaker
(4) flat-bottom flask, rubber cork, small glass tube, water, KOH solution, delivery tube, dry seeds, thread, vaseline, small beaker
Answer:
For the above mentioned experiment, the following apparatus is required – flat-bottom flask, rubber cork (to close the flask), small glass tube (to keep KOH), water, KOH solution (to absorb CO₂), delivery tube, germinating seeds, thread (to hang the KOH tube), vaseline (to seal the flask and rubber crok), small beaker
Hence, the correct answer is option 1.

Question 75.
In the experiment to demonstrate that starch is made as food by the process of photosynthesis, the plucked leaf is first boiled in water for about 3 to 5 minutes in order to .
(1) remove chlorophyll from leaf cells
(2) break down the cell membranes of leaf cells
(3) soften the brittle leaf
(4) convert starch into glucose so that is can be tested easily
Answer:
In the above mentioned experiment, the plucked leaf is first boiled in water for about 3 to 5 minutes in order to remove the chlorophyll from leaf cells. It is done to destarch the leafs.
Hence, the correct answer is option 1.

Lakhmir Singh Biology Class 10 Solutions

Lakhmir Singh Biology Class 10 Solutions Model Test Paper 2

May 20, 2022

S Chand Biology Class 10 Solutions Model Test Paper 2

Question 1.
How is the increase in demand for energy affecting our environment adversely?
Answer:
As the population increases, so does their demand for energy. More and more of fossil fuels are being used to generate electricity and for transportation purposes. Use of fossil fuels in large amounts, add heat and pollution to the environment thus affecting the climatic conditions and the environment adversely.

Question 2.
Balance the following chemical equation.
\(\mathrm{FeSO}_{4} \stackrel{\text { Heat }}{\longrightarrow} \mathrm{Fe}_{2} \mathrm{O}_{3}+\mathrm{SO}_{2}+\mathrm{SO}_{3}\)
Answer: Balanced chemical equation.
\(2 \mathrm{FeSO}_{4} \stackrel{\mathrm{Heat}}{\longrightarrow} \mathrm{Fe}_{2} \mathrm{O}_{3}+\mathrm{SO}_{2}+\mathrm{SO}_{3}\)

Question 3.
Draw ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed.
(a) at 2F₁
(b) between F₁ and the optical center O of the lens
Answer:
(a) When the object is at 2F₁

Nature of the image formed. Real and inverted
Position of the image formed. At 2F₂
Size of the image formed. Same as that of the object

(b) When the object is placed between the focus F₁ and optical center O.

Nature of the image formed. Virtual and erect
Position of the image formed. Same side of the object, beyond the 2F₁
Size of the image formed. Enlarged

Question 4.
Give an example of a decomposition reaction. Describe an activity to illustrate such a reaction by heating.
Answer:
A decomposition reaction is a chemical reaction in which a single compound breaks down to simpler products.
Example. Decomposition of ferrous sulphate crystals.

Heat the ferrous sulphate crystals, the colour of ferrous sulphate crystals is green. On heating, the ferrous sulphate crystals lose their water molecules. Therefore, the colour of the crystals change.

Question 5.
Write one function each of the following components of the transport system in human beings.
(a) Blood vessels
(b) Blood platelets
(c) Lymph
(d) Heart
Answer:
(a) Blood vessels help in transporting oxygenated and deoxygenated blood to different parts of the body.
(b) Platelets help in the process of blood clotting.
(c) Lymph carries digested and absorbed fats from the intestine. It also provides immunity to the body.
(d) Heart acts as a pump and helps circulate blood throughout the body.

Question 6.
Name two metals which react violently with cold water. Write any three observations you would make when such a metal is dropped into water. How would you identify the gas evolved, if any, during the reaction?
Answer:
Sodium and potassium are two metals that react violently with cold water.
Observations made when such a metal is dropped in water.

The reaction is highly exothermic, i.e. a huge amount of heat is produced.
Hydrogen gas is evolved in the reaction
Little explosions take place because the heat produced in the chemical reaction burns the hydrogen gas.

Hydrogen gas can be identified by the pop sound produced during the reaction of metal with cold water.

Question 7.
(a) Why are covalent compounds generally poor conductors of electricity?
(b) Name the following compound.

(c) Name the gas evolved when ethanoic acid is added to sodium carbonate. How would you prove the presence of this gas?
Answer:
(a) As covalent bonds do not break easily (dissociate), so they do not form ions which help in conduction of electricity. Therefore, covalent compounds don’t conduct electricity as they don’t have free electrons or ions.
(b) The given compound contains 3 carbons and a ketone functional group so it would be called as ‘propanone’.
(c) When ethanoic acid reacts with sodium carbonate, sodium ethanoate, carbon dioxide, and water are formed.
\(2 \mathrm{CH}_{3} \mathrm{COOH}+\mathrm{Na}_{2} \mathrm{CO}_{3} \rightarrow \mathrm{CH}_{3} \mathrm{COONa}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}\)
To test the presence of formed gas, we pass this gas from lime water. Upon reaction, lime water turns milky, which confirms the presence of carbon dioxide in the reaction.

Question 8.
(a) What is the difference between washing soda and baking soda?
(b) Write the chemical formula for bleaching powder. How is bleaching powder prepared? For what purpose is it used in paper factories?
Answer:
(a) Washing soda: Chemical formula of washing soda is Na₂CO₃. 10H₂O Washing soda used as a cleansing agent in domestic household purposes.
Baking Soda: Chemical formula of baking soda is NaHCO₃. Baking soda is used as an antacid to remove acidity in the stomach.

(b) The chemical formula of bleaching powder is CaOCl₂.
Bleaching powder is prepared by passing chlorine gas over dry calcium hydroxide.

Bleaching powder is used in paper factories for bleaching wood pulp, as bleaching powder is a strong oxidizing agent.

Question 9.
In the electrolysis of acidified water.
(a) Name the gas collected at (i) anode, and (ii) cathode
(b) Why is the volume of gas collected at one electrode double than that at the other electrode?
(c) What would happen if dilute sulphuric acid is not added to water?
Answer:
(a) Electrolysis of acidified water.
At cathode: 2H⁺ + 2e^– → H₂
At anode: OH^– → OH + e^–
4OH → 2H₂O₂
Hence, the gas produced at cathode is hydrogen and the gas produced at anode is oxygen.

(b) A water molecule contains two atoms of hydrogen and one atom of oxygen. Therefore, during the electrolysis of water, the ratio of the amount of hydrogen gas and oxygen gas produced is 2.1. Hence, we can say that the volume of gas collected at one electrode is double than that at the other electrode

(c) As electrolysis of water is a slow process, to increase the rate of electrolysis we add dilute sulphuric acid.
Dilute sulphuric acid increases the rate of breakdown of ions.

Question 10.
Two lamps, one rated 40 W at 220 V and the other 60 W at 220 V, are connected in parallel to the electric supply at 220 V.
(a) Draw a circuit diagram to show the connections.
(b) Calculate the current drawn from the electric supply.
(c) Calculate the total energy consumed by the two lamps together when they operate for one hour.
Answer:
(a)

(b) Using, I = \(\frac{P}{V}\)
Current drawn by 60 W lamp is, I = \(\frac{220}{60}\) = 3.67 A
Current drawn by 40 W lamp is, I = \(\frac{220}{40}\) = 5.5 A
So, the net current drawn by the combination is = 3.67 A + 5.5 A = 9.17 A
(c) Net power of the combination = 60 W + 40 W = 100 W
So, the energy consumed in 1 h = E = P × t = 100 × 1 × 60 × 60 J = 360000 J

Question 11.
(a) Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
(b) Draw a diagram to show the magnetic field lines around a bar magnet. List any two properties of magnetic field lines.
Answer:
(a) A series arrangement not used for connecting domestic electrical appliances in a circuit because if any one of the components connected in series stops working or get damaged, then the whole circuit would break up and no current will flow further in the circuit and none of the other devices would work.
(b)

Two properties of magnetic field lines.

They originate from the north pole of the magnet and end at the south pole of the magnet.
They do not intersect each other.

Question 12.
Name the electric device which converts mechanical energy into electrical energy. Draw the labelled diagram and explain the principle involved in this device.
Answer:
An electric generator converts mechanical energy into electrical energy.

MNST → Rectangular coil
A and B → Brushes
C and D → Two slip rings
X → Axle, G → Galvanometer
The principle of working of an electric generator is that when a loop is moved in a magnetic field, an electric current is induced in the coil. It generates electricity by rotating a coil in a magnetic field. The above figure shows a simple AC generator.

Question 13.
Write any three differences between aerobic and anaerobic respiration.
Answer:

Aerobic Respiration	Anaerobic respiration
It involves the complete breakdown of glucose into CO₂ and H₂O.	It involves the partial breakdown of glucose.
It occurs in the presence of oxygen.	It occurs in the absence of oxygen.
A net gain of 36 molecules of ATP occurs.	A net gain of only 2 molecules of ATP occurs.
Occurs in plants and animals (eukaryotes).	Occurs in human muscle cells. bacteria, yeast etc.

Question 14.
How is ozone formed in the upper atmosphere? Why is damage to ozone layer a cause of concern to us? What causes this damage?
Answer:
Ultraviolet radiations split the oxygen molecules present in stratosphere into free oxygen atoms. These free oxygen atoms then combine with molecular oxygen to form ozone.
O₂ → O + O
O₂ + O → O₃
Ozone layer is a protective layer which protects the earth from harmful UV radiations. Any damage to the ozone layer would result in UV rays entering the earth’s atmosphere. These UV rays can cause diseases such as skin cancer and cataract.
They can also adversely affect the crops.
The ozone layer is damaged as a result of chlorofluorocarbons. These are often used in refrigerators, air conditioners and fire extinguishers.

Question 15.
(a) State one difference between arteries and veins.
(b) Name any two sexually transmitted diseases. What advice is given to prevent them?
Answer:
(a)

Arteries	Veins
They carry oxygenated blood from the heart to the other parts of the body. The pulmonary artery is an exception as it carries deoxygenated blood from the heart to lungs.	They carry deoxygenated blood from the body to the heart. The pulmonary vein is an exception as it carries oxygenated blood from the heart to lungs.

(b) Syphilis and AIDS are two sexually transmitted diseases. Such diseases can be prevented by the use of condoms.
Condoms are made of thin rubber and are used to cover the penis and the vagina in males and females, respectively.

Question 16.
(a) What is meant by the dispersion of white light? Describe the formation of the rainbow in the sky with the help of a diagram.
(b)What is hypermetropia? Draw ray diagrams to show the image formation of an object by.
(i) Hypermetropic eye
(ii) Correction made with a suitable lens for the hypermetropic eye.
Answer:
(a) The splitting of white light into seven colors on passing through a transparent glass prism is called dispersion of white light.
A rainbow is formed in the sky because of the dispersion of sunlight by millions of water droplets in the atmosphere. Every single water droplet behaves like a tiny glass prism that splits the white light into different colors. Different colors bend at different angles on passing through the water droplets, thus separating the white light into a natural spectrum of seven colors, as Violet, Indigo, Blue, Green, Yellow, Orange, and Red. The diagram below shows the formation of a rainbow.

(b) Hypermetropia or long-sightedness is a common eye defect, in which a person is not able to nearby objects whereas the farther objects appear clear to the person.
(i) Hypermetropic eye.

(ii) Correction made with a convex lens for the hypermetropic eye.

Question 17.
(a) Give reasons for the following.
(i) Colour of the clear sky is blue.
(ii) The sun can be seen about two minutes before the actual sunrise.
(iii) We cannot see an object clearly if it is placed very close to the eyes.
(b) What is Presbyopia? Write two causes of this defect.
Answer:
(a) (i) The sky appears blue when viewed from Earth, because of the scattering of the light. When sunlight strikes molecules in our atmosphere, the light is redirected in many directions. The blue light is scattered more than the red light because blue color has the smallest wavelength i.e. comparable to the size of the particles present in our atmosphere. So, it is scattered the most, causing the sky to be blue.

(ii) The Sun is visible to us two minutes before the sunrise and two minutes after the sunset because of the bending of the light due to atmospheric refraction. The light from the Sun gets refracted by the atmospheric layers and reaches the observer. This causes the observer to think that the light is coming straight from the Sun.

(iii) If an object is placed very close to the eyes, the light reflected from it does not fall on the retina to form a clear image. The minimum distance for seeing an object clearly is 25 cm for the human eye.

(b) Presbyopia is a common defect of vision, which generally occurs at old age. A person suffering from this type of defect of vision cannot see the nearby objects clearly and distinctively. A presbyopic eye has its near point greater than 25 cm and it gradually increases as the eye becomes older.
Presbyopia is caused by the.
1. The weakening of the ciliary muscles.
2. Reduction in the flexibility of the eye lens.

Question 18.
(a) Why do we classify elements?
(b) What were the two criteria used by Mendeleev in creating his Periodic Table?
(c) Why did Mendeleev leave some gaps in his Periodic Table?
(d) In Mendeleev’s Periodic Table, why was there no mention of Noble gases such as Helium, Neon and Argon?
(e) Would you place the two isotopes of chlorine, Cl-35 and Cl-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.
Answer:
(a) The need to classify elements into families with similar properties arose because, lacking this basic tool, the chemist had to deal with each of the 45 or so known elements one at a time, as if there were no rhyme or reason to them.

(b) Two criteria used by Mendeleev in creating his periodic table.
(i)Mendeleev’s periodic table was based on the observation that the properties of elements are the function of their atomic masses. This means that if elements are arranged in the increasing order of their atomic masses, then their properties get repeated after regular intervals.
(ii) Relative atomic mass and similarity of chemical properties.

(c) As at the time of Mendeleev some elements are not discovered, so he realized this fact and left gaps in his table for such elements and also predicted their properties.

(d) Because at the time of Mendleeve these elements are not discovered, so he did not mention about them.
(e) In the modern periodic table, all isotopes are placed in the same position as in modern periodic table is based on the atomic number not on atomic masses.

Question 19.
(a) Show the formation of Na2O by the transfer of electrons between the combining atoms.
(b) Why are ionic compounds usually hard?
(c) How is it that ionic compounds in the sold state do not conduct electricity but they do so when in molten state?
(d) What type of chemical bonds are present in CCl4?
(e) What type of chemical bonds are present in MgCl2?
Answer:
(a) Electronic configuration of Na₂O.

Formation of ionic bond.

(b) Ionic compounds are usually hard because of inter-atomic attractive forces between them. Positively charged ion and negatively charged ion are strongly attracted towards each other and their lattice enthalpy increases.

(c) Electricity can be conducted only in the presence of free electrons/ions. In the solid state, there will be no free electrons but in the molten state, ions are free to conduct electricity.

(d) In carbon tetrachloride, four single bonds are formed. Hence, covalent bonding is present in CCl4.

(e) In magnesium chloride, magnesium will lose its electrons and chlorine will accept those electrons to form magnesium chloride. Hence. ionic bonding is present in magnesium chloride.

Question 20.
(a) Draw the structure of a neuron and label the following on it.
Nucleus, Dendrite, Cell body and Axon
(b) Name the part of neuron.
(i) where information is acquired.
(ii) through which information travels as an electrical impulse.
Answer:
(a)

(b)
(i) Dendrites acquire stimulus or information from the other cells.
(ii) Axon carries away information from the cell body to the dendrite of the next neuron.

Question 21.
(a) What is (i) phototropism, and (ii) geotropism? With labelled diagrams, describe an activity to show that light and gravity change the direction that plant parts grow in.
(b) Mention the role of each of the following plant hormones.
(i) Auxin
(ii) Abscisic acid
Answer:
(a) (i) The bending of shoots or other plant parts in response to light is known as phototropism.
(ii) The bending or growth of roots towards gravity is known as geotropism.
Activity –
Fill a conical flask with water and then cover the neck of the flask with a wire mesh. Place few germinating seeds on the wire mesh. Then, take a cardboard box that is open from one side. Place the flask in the box and keep this setup near a window. After 3-4 days, you will notice the shoots start bending towards light, while the roots bend away from light.

(b) (i) Auxin helps cells grow longer.
(ii) Abscisic acid inhibits growth and causes wilting of leaves.

Question 22.
(a) How will you test for the gas which is liberated when hydrochloric acid reacts with an active metal?
(b) Name any two active metals which can be used with hydrochloric acid to liberate the same gas.
Answer:
(a) When hydrochloric acid is treated with an active metal then hydrogen gas is released.
\(2 \mathrm{M}+2 \mathrm{HCl} \rightarrow 2 \mathrm{MCl}+\mathrm{H}_{2}\)
When this hydrogen gas comes in contact with burning match stick then the gas burns with a pop sound.
(b) Sodium and potassium are two active metals which can be used with hydrochloric acid to liberate the hydrogen gas.

Question 23.
Sunita performs two sets of experiments to study the formation of lather(foam) by using liquid soap.
Set 1 . She takes 10 ml of distilled water in test tube ‘A’, adds 5-6 drops of liquid soap in it and shakes the test tube vigorously.
Set 2 . She takes 10 ml of distilled water in test tube ‘B’, adds 5-6 drops of liquid soap in it alongwith half spoonful of CaSO4, and shakes the test tube vigorously.
(a) In which test tube, A or B, less lather is formed? Why?
(b) In which test tube, A or B, more lather is formed? Why?
Answer:
(a) Test tube “B” has less lather due to the presence of calcium ions. Due to the presence of calcium ions water become hard and in hard water, lather formation decreases.
(b) Test tube “A” has more lather because it is soft water. In soft water, lather formation increases and cleansing action increases.

Question 24.
(a) Copy this figure in your answer-book and show the direction of the light ray after reflection.

(b) What type of mirror is shown in the above figure. a converging mirror or a diverging mirror?
Answer:
(a) The ray will get reflected from the mirror and will go parallel to the principal axis of the mirror.

(b) The mirror shown in the given figure is a converging mirror or a concave mirror.

Question 25.
A student is performing an experiment to verify Ohm’s Law in the laboratory. The ammeter given to him for this purpose has 10 divisions between 0 and 0.5 A on its scale. If the pointer shows 22 divisions on the ammeter scale while taking a reading, what is the value of current according to this position of pointer?
Answer:
The given ammeter has 10 division between 0 and 0.5 A.
Value of one division on the ammeter scale = 0.05 A
If the pointer shows 22 division for the main scale reading, then the actual reading = 22 × 0.05 A = 1.1 A
Hence, the value of the current according to the given pointer is 1.1 A.

Question 26.
In the test tubes A and B shown below, yeast was kept in sugar solution. Which products of respiration would you expect in tubes A and B?

Give reason for your answer.
Answer:
In test tube A, anaerobic respiration will occur. The top of test tube A is covered with a film of oil which means no oxygen would be available to the yeast cells for respiration. In this case, the product of respiration will be ethanol, carbon dioxide and energy.
Glucose → Pyruvate → 2C₂H5OH + 2CO₂ + 2ATP
In test tube B, aerobic respiration will occur. The products of aerobic respiration will be carbon dioxide, water and energy.
Glucose → Pyruvate → 6CO₂ + 6H₂O + 38ATP

Question 27.
Before testing the leaf for starch at the end of the experiment “Light is necessary for photosynthesis”.
(a) In which liquid the leaf should be boiled?
(b) Why should the leaf should be boiled in this liquid?
Answer:
(a) The leaf should be boiled in alcohol (ethanol).
(b) The leaf is boiled in alcohol to destarch it (remove the chlorophyll from the leaf) as the chlorophyll interferes with the testing of starch with iodine.

Lakhmir Singh Biology Class 10 Solutions

Lakhmir Singh Biology Class 10 Solutions Model Test Paper 3

May 20, 2022

S Chand Biology Class 10 Solutions Model Test Paper 3

Question 1.
Why is the red color selected for danger signal lights?
Answer:
The wavelength of red light is the longest in visible light, so the red color is scattered the least by air molecules of the atmosphere and therefore it can reach to a longer distance. That’s why the red color is used for danger signal lights.

Question 2.
Balance the following chemical equation.
MnO₂ + HCl → MnCl₂ + Cl₂ + H₂O
Answer:
Balanced chemical equation.
MnO₂ + 4HCl → MnCl₂ + Cl₂ + 2H₂O

Question 3.
What is the common name of CaSO₄. \(\frac{1}{2}\)H₂O ? Also name the compound from which it is prepared.
Answer:
The common name of CaSO₄. \(\frac{1}{2}\)H₂O is plaster of paris. Plaster of paris is obtained by heating gypsum (CaSO₄.2H₂O) at 373 K.

Question 4.
What is the resultant resistance of the three resistors of 5 Ω, 4 Ω and 10 Ω connected as shown in the figure? What is this combination of resistors known as?

Answer:
This given combination of resistors is known as parallel combination.
In a parallel combination, the reciprocal of the resultant resistance is equal to the sum of reciprocals of the individual resistances present in the combination. For the three resistors connected in parallel,

Question 5.
Define variation in relation to a species. Why is variation beneficial to the species?
Answer:
The occurrence of differences among the individuals of the same species is known as variation.
Variation helps in the survival of species by bringing about changes in the basic body design, thereby providing the organisms with a better adaptability against predators.

Question 6.
(a) Show on a diagram the transfer of electrons between the atoms in the formation of MgO.
(b) Name the solvent in which ionic compounds are generally soluble.
(c) Why are aqueous solutions of ionic compounds able to conduct electricity?
Answer:
(a) Transfer of electrons between atoms in the formation of magnesium oxide.

(b) Water is the best solvent in which ionic compounds are generally soluble.
(c) The aqueous solution of ionic compounds can conduct electricity because of the presence of free ions. These ions are responsible for the conduction of electricity in aqueous solutions.

Question 7.
Explain why, the blue colour of copper sulphate solution fades when an iron nail is kept dipped in it. Write chemical equation of the reaction involved. What does this reaction tell us about the relative reactivities of copper and iron?
Answer:
When an iron nail is put in the blue colour copper sulphate solution, then the iron displaces copper from copper sulphate and forms green coloured iron sulphate solution, that’s why the blue colour of the solution fades. The reaction involved is as follows.

As iron displaces copper from its sulphate solution, so, we can conclude that iron is more reactive than copper.

Question 8.
Why are decomposition reactions called the opposite of combination reactions? Explain by giving one example (with equation) of each type of reaction.
Answer:
Decompositon reaction are those in which a compound breaks down to form two or more substances. These reaction require a source of energy to proceed. Thus, they are the exact opposite of combination reactions in which two or more substances combine to give a new substance with the release of energy.
Decomposition reaction. \(2 \mathrm{H}_{2} \mathrm{O} \stackrel{\text { electrolysis }}{\longrightarrow} 2 \mathrm{H}_{2}+\mathrm{O}_{2}\)
Combination reaction. 2H₂ + O₂ → 2H₂O + energy

Question 9.
The atom of an element has the electron structure 2, 7.
(a) What is the atomic number of the element?
(b) To which of the following would it be chemically similar?
₇N, ₁₅P, ₁₇Cl, ₁₈Ar
(c) Why would you expect it to be similar?
Answer:
(a) The atomic number of the element is 9.
(b) Out of given options, ₁₇Cl has similar properties with this element.
Electronic configuration of Cl is 2, 8, 7. So, valence shell contains 7 electrons.
(c) The modern periodic table assumes that elements with the same number of valence electrons have similar properties.

Question 10.
The position of hand shown in the figure corresponds to one of the Fleming’s rules.

(a) Which Fleming’s rule is illustrated by this hand?
(b) In this figure of hand, what is indicated.
(i) by the direction of forefinger?
(ii) by the direction of center finger?
(iii) by the direction of thumb?
Answer:
(a) Fleming’s left-hand rule is illustrated by the hand.
(b) (i) The magnetic field is indicated by the direction of fore-finger.
(ii) Electric current is indicated by the direction of the center finger.
(iii) By the direction of thumb, the motion of the conductor is indicated in the given figure.

Question 11.
Two resistors, with resistances 5 Ω and 10 Ω respectively are to be connected to a battery of emf 6 V so as to obtain. (i) minimum current flowing (ii) maximum current flowing.
(a) How will you connect the resistances in each case?
(b) Calculate the strength of the total current in the circuit in two cases.
Answer:
(a) In a parallel combination of resistances, the net resistance is less as compared to a series combination of resistances. As the current flow is indirectly proportional to the resistance of the circuit, so to obtain maximum current flowing in the circuit the given resistances should be connected in parallel combination and to obtain the minimum current flowing the given resistances should be connected in series combination.

(b) Case (i) For minimum current flow, the resistance of the circuit should be maximum. i.e. resistances should be connected in Series.
Net resistances of given resistances when connected in series = 5 Ω + 10 Ω = 15 Ω
The voltage of the battery = 6 V
Hence, current = \(\frac{6 \mathrm{V}}{15 \Omega}\) = 0.4 A
Case (ii) For maximum current flow, the resistance of the circuit should be minimum. i.e. resistances should be connected in parallel.
Net resistances of given resistances when connected in parallel = \(\frac{5 \Omega \times 10 \Omega}{5 \Omega+10 \Omega}=\frac{10}{3} \Omega\)
The voltage of the battery = 6 V
Hence, current = \(\frac{6 \mathrm{V}}{\frac{10}{3} \Omega}\) = 1.8 A

Question 12.
What is hypermetropia? State the two causes of hypermetropia. With the help of ray diagrams, show.
(a) the eye-defect hypermetropia
(b) correction of hypermetropia by using a lens
Answer:
Hypermetropia or long-sightedness is a common eye defect, in which a person is not able to see nearby objects whereas the farther objects appear clear to the person.
Two causes of hypermetropia.
(i) Eyeball being too short.
(ii) The increased focal length of the eye lens.
(a) Hypermetropic eye.

(b) Correction made with a convex lens for the hypermetropic eye.

Question 13.
Distinguish between biodegradable and non-biodegradable substances. List two effects of each of them on our environment.
Answer:

Biodegradable Substance	Non-biodegradable Substance
It decomposes naturally in the environment by the action of microorganisms.	It does not decompose naturally.
It is environment friendly.	It is harmful to the environment and causes pollution.
It is made up of natural ingredients.	It is made up of synthetic materials.
It can be converted into manure or recycled.	It can be either reused or recycled.
Examples: Waste paper, wood crumbles, etc.	Examples: Plastic bags, cans, disposable bottles, etc.

Effects of biodegradable substances on environment –

Decomposition of biodegradable wastes is accompanied by foul smell which spreads in the environment and affects the people in nearby areas.
Heaps of biodegradable wastes act as breeding grounds for houseflies etc, which act as vectors of various diseases.

Effects of non-biodegradable substances on environment –

Excessive use of non-biodegradable pesticides and fertilizers affect the fertility of soil.
Certain non-biodegradable wastes enter the food chains, get biomagnified and affect the various biotic components of environment.

Question 14.
Why are bacteria and fungi called decomposers? List any two advantages of decomposers to the environment.
Answer:
Bacteria and fungi are called decomposers as they obtain nutrients by breaking down the remains of dead plants and animals.
Role of decomposers

They help in the breakdown of organic matter or biomass of dead plants and animals into simple inorganic raw materials such as CO₂, H₂O and nutrients.
They help in the natural replenishment of soil.

Question 15.
(a) Name two different ways in which glucose is oxidized to provide energy in various organisms.
(b) Write any two differences between the two ways of oxidation of glucose in organisms.
Answer:
(a) Glucose can undergo either aerobic or anaerobic respiration to provide energy.
(b)

	Anaerobic respiration	Aerobic Respiration
(i)	It involves the partial breakdown of glucose.	It involves the complete breakdown of glucose into CO₂ and H₂O.
(ii)	A net gain of only 2 molecules of ATP occurs.	A net gain of 36 molecules of ATP occurs.

Question 16.
(a) Which two criteria did Mendeleev use to classify the elements in his periodic table?
(b) State Mendeleev’s periodic law.
(c) Why could no fixed position be given to hydrogen in Mendeleev’s periodic table?
(d) How and why does the atomic size vary as you go.
(i) from left to right along a period?
(ii) down a group?
Answer:
(a) Two criteria used by Mendeleev in creating his periodic table.
(i)Mendeleev’s periodic table was based on the observation that the properties of elements are the function of their atomic masses. This means that if elements are arranged in the increasing order of their atomic masses, then their properties get repeated after regular intervals.
(ii) Relative atomic mass and similarity of chemical properties.

(b) Mendeleev’s periodic law states that the physical and chemical properties of elements are the periodic function of their atomic weights.

(c) hydrogen has atomic mass 1 so definitely, it must be in the first period but the group was confusing. He found that hydrogen forms oxides like alkali earth metals with formula H₂O as Na₂O. He also found that hydrogen is similar to halogens in forming diatomic molecules H₂ like Cl₂, Br₂. So, he could not assign a fixed position to hydrogen.

(d)
(i) On moving left to right in a period, atomic size decreases because of the number of electron increases due to which attractive forces towards nucleus increases and atomic size decreases.
(ii) On moving down the group, atomic size increases due to the increase in valence shells.

Question 17.
Write the names and symbols of the two most reactive metals belonging to the Group I of the periodic table. Explain by drawing electronic structure how either one of the two metals reacts with a halogen. With which name is the bond formed between these elements known and what is the class of the compound so formed known? State any four physical properties of such compounds.
Answer:
The two most reactive elements of group 1 are cesium (Cs) and rubidium(Rb). Since valence shell of cesium contains only 1 electron, so it can lose it and form positive Cs+ ion. The electron lost by cesium can be accepted by halogen atom like chlorine and form negative chloride ions. The positive and negative ions attract each other to form electrostatic bond also called ionic bond. This type of compound formed is called an ionic compound.
Electronic configuration of cesium chloride.

Properties of the ionic compound are.

High melting and boiling point.
Good electrical conductivity in the molten state and aqueous solution.
Physical state is usually crystalline solid.
Soluble in water.

Question 18.
(a) What is a solenoid? Draw a sketch of the pattern of field lines of the magnetic field through and around a current carrying solenoid.
(b) Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right hand rule to find out the direction of the magnetic field inside and outside the loop.
Answer:
(a) A solenoid is a long coil that contains a large number of close turns of insulated copper wire. The magnetic field pattern produced by a current-carrying solenoid is similar to the magnetic field produced by a bar magnet.

(b)

We can apply the right-hand thumb rule to determine the direction of magnetic field lines around a current caring circular wire.
Here, the current is flowing into the clockwise direction, hence the direction of magnetic field lines inside the loop is going inward the table and the direction of the magnetic field outside the loop is coming out of the table. As shown in the above figure.

Question 19.
Derive the expression for the heat produced to a current ‘I’ flowing for a time interval ‘t’ through a resistor ‘R’ having a potential difference ‘V’ across its ends. With which name is the relation known? How much heat will an instrument of 12 W produce in one minute if it is connected to a battery of 12 V?
Answer:
Heat energy = power consumed × time
∴ H = P × t
Let ‘I’ is the current flowing for a time interval ‘t’ through a resistor ‘R’ having a potential difference ‘V’ across its ends.
Power = I²R or \(\frac{V^{2}}{R}\)
∴ H = I²Rt or \(\frac{V^{2}}{R} t\)
This relation is known as Joule’s law of heating.
Power of the instrument = 12 W
Time for which the instrument is used = 1 minute = 60 Seconds
Heat produced = P × t = 12 W × 60 s = 720 J

Question 20.
(a) Draw a diagram of human alimentary canal and label on it.
Oesophagus, Gall bladder, Liver and Pancreas
(b) Explain the statement, ‘Bile does not contain any enzyme but it is essential for digestion.’
Answer:
(a)

(b) Bile does not contain any enzyme, but it plays an important role in digestion as it performs the following functions.

The bile salts break down large fat globules into smaller globules so that the pancreatic enzymes can easily act on them. This is referred to as emulsification of fats.
The food entering the small intestine is acidic which has to be made alkaline so that the pancreatic enzymes can act on it. This function is also performed by bile juice.

Question 21.
(a) Draw a diagram of excretory system in human beings and label on it.
Aorta, vena cava, urinary bladder, urethra.
(b) List two vital functions of the kidney.
Answer:
(a)

[Note. Aorta and vena cava are components of the circulatory system.]
(b) The two vital functions of kidney are.

filters the wastes out of the blood and forms urine
maintains the water balance of the body

Question 22.
Draw the following diagram in your answer-book and show the formation of the image of the object AB with the help of suitable rays.

What type of reflecting surface is shown in the above diagram?
Answer:
Image formation is as follows.

The above-shown reflecting surface is a converging surface of a concave mirror.

Question 23.
A student was given three resistors of 2 ohms, 3 ohms and 5 ohms by his teacher. The teacher asked him to connect these three resistors in such a way so as to obtain the minimum resistance.
(a) In what way should the student connect the resistors?
(b) Draw a diagram of the combination of resistors.
Answer:
In a parallel combination, the resultant resistance is always less than or equal to the smallest resistance in the combination. So, a parallel combination of resistances gives the minimum resistance.
(a) Hence, in order to get minimum resistance, the student needs to arrange them in a parallel combination.
(b) A parallel combination of given resistors is shown below.

Question 24.
When a student adds some dilute hydrochloric acid to baking soda taken in a test-tube, a gas is evolved.
(a) Name the gas evolved.
(b) How can this gas be tested?
Answer:
When a student add dilute hydrochloric acid to baking soda(NaHCO₃), the aqueous solution of sodium chloride, carbon dioxide gas, and water are obtained.
HCl(aq) + NaHCO₃(aq) → NaCl(aq) + CO₂(g) + H₃O(l)
(a) So, the gas evolved is carbon dioxide.
(b) When we pass this gas from lime water, it turns the lime water milky and its presence is confirmed.

Question 25.
A student was given two test-tubes A and B each containing a colourless solution. When a few drops of universal indicator were added to the two test-tubes, one by one, then the colour of solution in test-tube A changed to blue whereas the colour of solution in test-tube B changed to orange.
(a) Which test-tube has a solution of pH higher than 7?
(b) Which test-tube has a solution of pH lower than 7?
(c) Which test-tube has an acidic solution?
(d) Which test-tube has an alkaline solution?
Answer:
(a) The universal indicator changes its color towards violet in basic or alkaline medium. This, the pH of the solution in test tube A is greater than 7, that’s why the universal indicator shows blue colour.
(b) The universal indicator changes its color towards red in acidic medium. So, the pH of the solution in test tube B is less than 7, that’s why the universal indicator is giving an orange colour.
(c) The pH of the solution in the test tube B is less than 7, so the test tube “B” has an acidic solution.
(d) The pH of the solution in test tube A is greater than 7, so test tube “A” has an alkaline solution.

Question 26.
A student conducted an experiment to show that carbon dioxide is released during respiration. State two precautions that the student must take for obtaining correct observations.
Answer:
Two precautions which should be taken during performing the experiment to show that carbon dioxide is produced during respiration are

The conical flask should be air tight so that the CO2 produced during the experiment does not escape and a partial vacuum can be created in the flask.
Germinating seeds should be used in the experiment because germinating seeds produce CO2 which has to be tested in this experiment.

Question 27.
A star-shaped figure was cut in the black paper strip used for covering a part of the leaf of a destarched plant used for demonstrating that light is necessary for photosynthesis. At the end of the experiment (after the removal of chlorophyll), the leaf was tested for starch with iodine solution.

(a) What colour, if any, will be produced on the part of leaf under the star-shaped figure?
(b) Give reason for your answer.
Answer:
(a) The part of leaf under the star region will show blue black colour upon testing with iodine.
(b) The appearance of blue colour in that part indicates the presence of starch.

Lakhmir Singh Biology Class 10 Solutions

Lakhmir Singh Biology Class 10 Solutions Model Test Paper 4

May 20, 2022

S Chand Biology Class 10 Solutions Model Test Paper 4

Question 1.
Name a reducing agent that may be used to obtain manganese from manganese dioxide.
Answer.
Aluminium powder is used as the reducing agent to obtain manganese from its oxide.
2Al(s) + 3MgO → Al₂O₃ + 3Mg(s)

Question 2.
Why does a ray of light bend when it travels from one medium into another?
Answer.
When a light ray travels from one medium to another, then due to change in the density of the medium, speed of light changes. Change in the speed of the light at the boundary of two media force the light ray to bend from its original path.

Question 3.
A compound which is prepared from gypsum has the property of hardening when mixed with a proper quantity of water. Identify the compound. Write the chemical equation for its preparation. For what purpose is it used in hospitals?
Answer.
When gypsum is heated at 373 K, it gives plaster of paris,

Plaster of paris becomes hard when the appropriate amount of water is available.

In hospitals, it is used as a plaster to support broken or fractured bones.

Question 4.
What is the minimum number of rays required for locating the image formed by a concave mirror for an object. Draw a ray diagram to show the formation of a virtual image by a concave mirror.
Answer.
Only two rays are required for the image to be located.
Image diagram to show the formation of a virtual image formed by a concave mirror.

Question 5.
Name the type of respiration in which the end products are.
(a) ethanol, carbon dioxide and energy.
(b) carbon dioxide, water and energy.
Answer.
(a) ethanol, carbon dioxide and energy – Anaerobic respiration
(b) carbon dioxide, water and energy – Aerobic respiration

Question 6.
Name the functional group of organic compounds that can be hydrogenated. With the help of suitable example, explain the process of hydrogenation mentioning the conditions of the reaction and any one change in physical property with the formation of the product. Name any one natural source of organic compounds that are hydrogenated.
Answer.
Functional group that can be hydrogenated is alkene.
Hydrogenation of oils(unsaturated alkene).

Vegetable oil is unsaturated fatty acids having a double bond in between some of their carbon atoms. When vegetable oil is heated in the presence of nickel catalyst, then a saturated fatty acid called vegetable ghee is formed. This reaction is known as a hydogenation reaction.
When vegetable oil is hydrogenated, it changes from liquid state to solid state.

Vegetable ghee is generally produced by hydrogenation of vegetable oil or animal oil.

Question 7.
No chemical reaction takes place when granules of a solid, A, are mixed with the powder of another solid, B. However, when the mixture is heated, a reaction takes place between its components. One of the products, C, is a metal and settles down in the molten state while the other product, D, floats over it. It was observed that the reaction was highly exothermic.
(a) Based on the given information, make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of the reaction.
(b) Mention any two types of reactions under which above chemical reaction can be classified.
Answer.
(a) Solid A is assumed to be aluminium (Al) and solid B to be manganese oxide. When the mixture of manganese oxide and aluminium is heated, manganese is produced in the molten state and aluminium oxide floats over it. Manganese produced in the molten state as a lot of heat energy is released in the process. Therefore, C is manganese and D is aluminium oxide.
Al(s) + MnO₂(s) → Mn(s) + Al₂O₃(s)
(b) The type of reaction under which the above reaction is classified are.
1. Redox reaction
2. Displacement reaction

Question 8.
Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electronic shells but different number of electrons in their outermost shells. It was found that elements A and G combine to form an ionic compound which can also be extracted from sea water. Oxides of the elements A and B are basic in nature while those of E and F are acidic.
The oxide of element D is almost neutral. Answer the following Qs based on the information given herein.
(a) To which group or period of the periodic table do the listed elements belong?
(b) Which one of the eight elements is likely to be a noble gas?
(c) Which one of the eight elements would have the largest atomic radius?
(d) Which two elements amongst these are likely to be non-metals?
(e) Which one of the these eight elements is likely to be a semi-metal or metalloid?
Answer.
(a) A and G form an ionic compound so A must be a metal of group 1 and G must be a non-metal of group 17. As the ionic compound of A and G is obtained from seawater so that ionic compound must be sodium chloride. Therefore, A and G belong to the third period of the periodic table.
(b) Because all the given elements belong to the third period and H being the last element of the third period will be the noble gas.
(c) A belongs to the first group of the periodic table, so it has the largest radius.
(d) Oxides of E and F are acidic in nature, so they are non-metals.
(e) The oxide of D is almost neutral, so it is a metalloid.

Question 9.
State, giving reasons, which of the following reactions will occur and which will not.
(a) MgSO₄ (aq) + Cu(s) → CuSO₄ (aq) + Mg(s)
(b) CuSO₄ (aq) + Fe (s) → FeSO₄ (aq) + Cu(s)
(c) MgSO₄ (aq) + Fe (s) → FeSO₄ (aq) + Mg(s)
Answer.
(a) MgSO₄ (aq) + Cu(s) → CuSO₄ (aq) + Mg(s)
Copper is less reactive than magnesium, so copper cannot displace magnesium. Hence, this reaction will not occur.
(b) CuSO₄ (aq) + Fe (s) → FeSO₄ (aq) + Cu(s)
Iron is more reactive than copper, so it will displace copper from copper sulphate and form iron sulphate.
(c) MgSO₄ (aq) + Fe (s) → FeSO₄ (aq) + Mg(s)
Iron is less reactive than magensium, so iron can not displace magnesium. Hence, this reaction will not occur.

Question 10.
Draw three labelled ray-diagrams to show the defect of vision called hypermetropia and how it is corrected by using a lens. Also name the lens used.
Answer.
Hypermetropia or long-sightedness is a common eye defect, in which a person is not able to nearby objects whereas the farther objects appear clear to the person.
Hypermetropia deffect.

Correction made with a convex lens for the hypermetropic eye.

A convex lens is used to correct the defect of hypermetropia.

Question 11.
At what distance should an object be placed from a convex lens of focal length 18 cm to obtain an image at 36 cm from it on the other side? What will be the magnification produced in this case?
Answer.
The focal length of the convex lens, f = +18 cm
Image distance, v = + 36 cm
Using lens formula, \(\frac{1}{v}-\frac{1}{u}=\frac{1}{f}\)
⇒ \(\frac{1}{36}-\frac{1}{u}=\frac{1}{18}\)
⇒ \(\frac{1}{u}=\frac{1}{36}-\frac{1}{18}=-\frac{1}{36}\)
⇒ u = -36 cm
Magnification of the lens = m = \(\frac{v}{u}=\frac{36 \mathrm{cm}}{-36 \mathrm{cm}}\) = -1

Question 12.
The magnetic field associated with a current carrying straight conductor is in an anticlockwise direction. If the conductor was held along the east-west direction, what will be the direction of current through it? Name and state the rule applied to determine the direction of the current.
Answer.
The direction of the flow of current can be found out by Maxwell’s Right Hand Thumb Rule. It states that if we point our right-hand thumb in the direction of current then the fingers of our hand curl along the direction magnetic field.
Now it is given that the magnetic field is in the anti-clockwise direction. If we look at the conductor from the right and apply the Thumb rule, the direction of current would be towards the East. However, if you look at the field from the left and apply this rule, the direction of current would be towards the west.

Question 13.
Explain analogous organs and homologous organs. Identify the analogous and homologous organs amongst the following.
Wings of an insect, wings of a bat, forelimbs of frog, forelimbs of a human.
Answer.
Analogous orgAnswer: These are organs that have different origins, but perform similar functions.
Homologous orgAnswer: These are organs that are similar in origin (or are embryologically similar), but perform different functions.
The wings of an insect and wings of a bat are examples of analogous organs.
The forelimbs of frog and forelimbs of humans are examples of homologous organs.

Question 14.
(a) Explain the terms.
(i) implantation (ii) placenta
(b) What is the average duration of human pregnancy?
Answer.
(a) (i) Implantation is the process wherein a fertilised egg (zygote) formed in the fallopian tube gets embedded on the walls of the uterus, inside the female body.
(ii) Placenta is a vascular structure present in the inner lining of the uterus. It is connected to the foetus by the umbilical cord. The embryo receives nutrition and oxygen from the mother’s blood via the placenta.
(b) The average duration of human pregnancy is nine months.

Question 15.
Explain the mechanism of reflex action with a suitable example.
Answer.
The automatic action or response provoked by a stimulus is known as reflex action. The sensory nerves that detect the stimulus are connected to nerves that move the muscles. Such a connection is called reflex arc. The reflex arc connections meet in a bundle in the spinal cord. The signal and the response that has taken place reach the brain but the brain does not coordinate the reflex response.
For example, we withdraw our hands on touching any hot article.

Question 16.
(a) Why did Mendeleev leave gaps in his periodic table?
(b) State any three limitations of Mendeleev’s classification.
(c) How does electronic configurations of atoms change in a period with increase in atomic number?
Answer.
(a) When Mendeleev developed the periodic table, he realized that many elements are missing in the periodic table and yet to be discovered. So, left gaps in his table for such elements and also predicted their properties.

(b) Limitations of Mendeleev’s classification.

He could not explain the position of isotopes in the periodic table.
He could not assign a proper position to the element hydrogen in the periodic table.
He failed to explain the wrong order of atomic masses of some elements.

(c) As we move from left to right in a period, the atomic number will increase due to the increase of electrons in the shell.

Question 17.
What is meant by refining of a metal? Name the most widely used methods of refining impure metals produced by various reduction processes. Describe with the help of a labelled diagram how this method may be used for refining of copper.
Answer.
Refining of metals. Refining of metals is nothing but the removal of impurities from crude metals or purifying the crude metal.
Electrolytic refining is the most widely used method for the refining of metals.
Electrolysis of copper.

Electrolysis of copper from copper sulphate solution is done using copper electrodes. The crude copper serves as the anode while the thin sheet of pure copper serves as the cathode.
At anode: Cu → Cu⁺² + 2e⁻
At cathode: Cu⁺² + 2e⁻ →Cu
As the anode dissolves away, the cathodes on which the pure metal is deposited grow in size.

Question 18.
Explain the process of digestion of food in mouth, stomach and small intestine in human body.
Answer.
The process of digestion of food in mouth, stomach and small intestine is described as follows.
1. Mouth – Digestion of food begins in the mouth. Saliva present in mouth contains a digestive enzyme, called salivary amylase, which breaks down starch into sugar.

2. Stomach – Stomach stores and mixes the food received from the oesophagus with gastric juices. The main components of gastric juice are hydrochloric acid, mucus and pepsinogen.
Hydrochloric acid dissolves bits of food and creates an acidic medium. In this medium, pepsinogen is converted to pepsin, which is a protein-digesting enzyme. Mucus protects the inner lining of the stomach from the action of HCl.

3. Small intestine – Small intestine is the site for complete digestion of carbohydrates, proteins and fats. It produces intestinal juice from the glands present in its wall. The intestinal juice helps in further digestion of food. Small intestine also obtains digestive juices from liver and pancreas that helps in mixing of food.
The liver produces bile juice that causes emulsification of fats and the pancreas produces pancreatic juice for digesting proteins and emulsified fats.
This digested food is finally absorbed through the intestinal walls.

Question 19.
(a) Define ‘Photosynthesis’. Apart from sunlight, what other conditions are necessary for the process of photosynthesis.
(b) Describe an experiment to show that “sunlight is essential for photosynthesis”.
Answer.
(a) Photosynthesis is the process by which plant cells prepare food (carbohydrates) from inorganic raw materials such as carbon dioxide and water in presence of sunlight and chlorophyll.

The factors other than sunlight affecting the rate of photosynthesis are.

Carbon dioxide − Carbon dioxide acts as the substrate for photosynthesis. During this process, carbon dioxide and water are converted into carbohydrates.
Water − During photosynthesis, water is photolysed into oxygen and hydrogen and it provides the energy for photosynthesis.
Chlorophyll − Chlorophyll is the green pigment present in the leaves which absorbs sunlight.

(b) Experiment to demonstrate that light is necessary for photosynthesis.

Take two potted plants. Place one plant in a dark room and the other in a room receiving sufficient sunlight.
After 3-4 days, take one leaf each from both the plants. Bathe the two leaves first in hot water and then in alcohol.
Add some drops of iodine solution on the leaves.

Observation.
It can be observed that the leaf taken from the plant kept in sunlight develops blue-black patches whereas the leaf taken from the plant kept in the dark room does not show any patches.

Reason for the observation.
Plants which receive sunlight prepare their own food through the process of photosynthesis. It is the presence of starch that turns the colour of iodine solution blue-black. Therefore, blue-black patches are observed on the leaf taken from the plant kept in sunlight. In contrast, the leaf of the plant kept in the dark room does not produce any starch. Therefore, no patches are observed on it.

Question 20.
(a) What is a magnetic field? How can the direction of magnetic field lines at a place be determined?
(b) State the rule for the direction of the magnetic field produced around a current-carrying conductor. Draw a sketch of the pattern of field lines due to a current flowing through a straight conductor.
Answer.
(a) The magnetic field is defined as the space surrounding a magnet in which magnetic force is exerted. The direction of magnetic field lines at a place can be determined by finding the deflection in the needle of a magnetic compass.
(b) The rule for determining the direction of the magnetic field of a current carrying wire is the right-hand thumb rule.

Right-hand thumb rule. The right-hand thumb rule indicates the direction of the magnetic field for a know direction of the current. If the thumb of the right-hand points along the direction of current then the curled fingers of that hand gives the direction of the magnetic field due to the current.

Question 21.
Explain with the help of a labelled circuit diagram how will you find the resistance of a combination of three resistors, of resistance R₁, R₂ and R₃ joined in parallel. Also mention how you will connect the ammeter and the voltmeter in the circuit when measuring the current in the circuit and the potential difference across one of the three resistors of the combination.
Answer.

Applied voltage = V
Let the current in the circuit = I
If total resistance of the circuit is R_net, then
I = \(\frac{V}{R_{\mathrm{net}}}\)
As all the resistances are connected in parallel, so all of the resistors will get an equal voltage across their ends.
The total current in the circuit is simply the sum of the current passing through each resistance.

An ammeter is low impedance device which is always connected in the series with the circuit so that maximum of the current can pass through it and it can give a more accurate value of the current flowing in the circuit.
A voltmeter is a high impedance device which is always connected in parallel in the circuit so that it does not draw any current and can give the actual voltage drop across the component.

Question 22.
Draw the given diagram in your answer book and complete it for the path of a ray of light beyond the lens.

(a) What type of lens is shown in this diagram?
(b) Is it a converging lens or a diverging lens?
Answer.

(a) A convex lens is shown in the diagram.
(b) It is converging in nature.

Question 23.
A student connects a coil of insulated wire to a galvanometer. What would be seen if a bar magnet with its north pole towards one face of the coil is.
(a) moved quickly towards it?
(b) moved quickly away from the coil?
(c) placed near the face of the coil?
Name the phenomenon involved.
Answer.
(a) When the bar magnet is moved quickly towards the coil, a deflection is observed in the galvanometer. This deflection indicates that some current is produced in the coil.

(b) When we move the magnet quickly away from the coil, this time the deflection is indicated in the opposite direction. It indicates the current produced in the coil is in the opposite direction.

(c) When we simply move the magnet near the face of the coil then no deflection is found in the galvanometer, because of the absence of relative motion between the coil and the magnet.

The phenomenon involved is known as Electromagnetic induction.

Question 24.
A student was working in a chemistry laboratory. He found that a bottle contained a white powdery substance but half of the label on the bottle was torn. The part of label still sticking to the bottle had NaH written on it. The student took this powdery substance in a test-tube and added dil. HCl to it. A gas was evolved which extinguished a burning match-stick.
(a) Name the gas evolved.
(b) Write the formula of white powdery substance.
Answer.
When dilute hydrochloric acid is mixed with that salt a gas is produced which extinguished a burning match-stick that means the gas produced is carbon dioxide.
So, the salt must be sodium bicarbonate.
HCl + NaHCO₃ → NaCl + H₂O + CO₂
(a) Hence, the gas produced is carbon dioxide.
(b) White powdery salt is sodium bicarbonate(NaHCO₃).

Question 25.
Ravi placed a zinc plate in a glass container having a blue coloured solution of a metal sulphate MSO4 for a considerable time. He found that the blue colour of solution got lighter and lighter, and finally the solution became colourless. A red-brown deposit was also formed on the zinc plate.
(a) Which metal, zinc or M, occurs lower in the reactivity series?
(b) Name the substance which forms colourless solution.
Answer.
When Ravi places zinc plate in a blue colored solution of metal sulphate, he found that colour of the solution is fading that means zinc is more reactive than that metal and displacing it from the solution. As the solution becomes colourless after some time it shows that metal M will be copper.
(a) Zinc is more reactive than metal M.
(b) Due to the formation of zinc sulphate solution becomes colourless.

Question 26.
A student is performing an experiment to show that sunlight is necessary for photosynthesis. In the first stage, he keeps a potted plant with green leaves in a dark place for about 3 days. Towards the end of the experiment, he boils one leaf in alcohol before using iodine for testing starch.
(a) Why is the plant kept in a dark place for about 3 days?
(b) Why is the leaf boiled in alcohol before testing for starch with iodine?
Answer.
(a) The plant is kept in dark so as to destarch it, so that in the beginning of the experiment itself, the leaves do not have any starch.
(b) After the plant is destarched by keeping it in dark, it is again placed in sunlight so that photosynthesis can occur. This would result in the synthesis of starch. The leaves are again destarched by boiling them in alcohol before testing them with iodine.

Question 27.
Pure-bred pea plants A are crossed with pure-bred pea plants B. It is found that the plants which look like A do not appear in F₁ generation but re-emerge in F₂ generation.
(a) Which of the plants A and B are. (i) tall, and (ii) dwarf?
(b) Give reason for your answer.
Answer.
(a) (i) Tall – Plant B
(ii) Dwarf – Plant A

(b) In pea plants, tallness is a dominant trait whereas dwarfness is a recessive trait. Plants like A do not appear in the F₁ generation but reappear in the F₂ generation which means that plant A is dwarf whereas plant B is tall.

We can see from the cross that, tall plants appear in the F₁ generation but no dwarf plants are seen.
The dwarf plants are seen in F₂ generation.

Lakhmir Singh Biology Class 10 Solutions

NCERT Solutions For Class 10 Maths Chapter 8 Introduction to Trigonometry Ex 8.2

May 20, 2022

Get Free NCERT Solutions for Class 10 Maths Chapter 8 Ex 8.2 Introduction to Trigonometry. Class 10 Maths NCERT Solutions are extremely helpful while doing homework. Exercise 8.2 Class 10 Maths NCERT Solutions were prepared by Experienced LearnCBSE.in Teachers. Detailed answers of all the questions in Chapter 8 Maths Class 10 Coordinate Geometry Exercise 8.2 Provided in NCERT Textbook.

Topics and Sub Topics in Class 10 Maths Chapter 8 Introduction to Trigonometry:

Section Name	Topic Name
8	Introduction to Trigonometry
8.1	Introduction
8.2	Trigonometric Ratios
8.3	Trigonometric Ratios Of Some Specific Angles
8.4	Trigonometric Ratios Of Complementary Angles
8.5	Trigonometric Identities
8.6	Summary

You can also download the free PDF of Chapter 8 Ex 8.2 Coordinate Geometry NCERT Solutions or save the solution images and take the print out to keep it handy for your exam preparation.

Board	CBSE
Textbook	NCERT
Class	Class 10
Subject	Maths
Chapter	Chapter 8
Chapter Name	Introduction to Trigonometry
Exercise	Ex 8.2
Number of Questions Solved	4
Category	NCERT Solutions

NCERT Solutions For Class 10 Maths Chapter 8 Introduction to Trigonometry Ex 8.2

NCERT Solutions for Class 10 Maths Chapter 8 Introduction to Trigonometry Ex 8.2 are part of NCERT Solutions for Class 10 Maths. Here we have given NCERT Solutions for Class 10 Maths Chapter 8 Introduction to Trigonometry Ex 8.2.

Ex 8.2 Class 10 Maths Question 1.
Evaluate the following:

Solution:

Ex 8.2 Class 10 Maths Question 2.
Choose the correct option and justify your choice:

Solution:

Download NCERT Solutions For Class 10 Maths Chapter 8 Introduction to Trigonometry PDF

Ex 8.2 Class 10 Maths Question 3.
If tan (A + B) = √3 and tan (A – B) = \(\frac { 1 }{ \surd 3 }\); 0° < A + B ≤ 90°; A > B, find A and B.
Solution:

Ex 8.2 Class 10 Maths Question 4.
State whether the following statements are true or false. Justify your answer.
(i) sin (A + B) = sin A + sin B.
(ii) The value of sin θ increases as θ increases.
(iii) The value of cos θ increases as θ increases.
(iv) sin θ = cos θ for all values of θ.
(v) cot A is not defined for A = 0°.
Solution:

NCERT Solutions for Class 10 Maths Chapter 8 Introduction to Trigonometry (Hindi Medium) Ex 8.2

NCERT Solutions for Class 10 Maths

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NCERT Solutions for Class 10 Social Economics Chapter 2 Sectors of Indian Economy

May 20, 2022

Formulae Handbook for Class 10 Maths and Science

NCERT Solutions for Class 10 Social Economics Chapter 2 Sectors of Indian Economy

Page 35
Q1: Fill in the blanks using the correct option given in the bracket:

(i) Employment in the service sector _________ increased to the same extent as production. (has / has not)
(ii) Workers in the _________ sector do not produce goods. (tertiary / agricultural)
(iii) Most of the workers in the _________ sector enjoy job security. (organised / unorganised)
(iv) A _________ proportion of labourers in India are working in the unorganised sector. (large / small)
(v) Cotton is a _________ product and cloth is a _________ product. (natural / manufactured)
(vi) The activities in primary, secondary and tertiary sectors are _________. (independent / interdependent)

Answer:
(i) Employment in the service sector has not increased to the same extent as production.
(ii) Workers in the tertiary sector do not produce goods.
(iii) Most of the workers in the organised sector enjoy job security.
(iv) A large proportion of labourers in India are working in the unorganised sector.
(v) Cotton is a natural product and cloth is a manufactured product.
(vi) The activities in primary, secondary and tertiary sectors are interdependent.

Q2: Choose the most appropriate answer.
(a) The sectors are classified into public and private sector on the basis of:
(i) employment conditions
(ii) the nature of economic activity
(iii) ownership of enterprises
(iv) number of workers employed in the enterprise

(b) Production of a commodity, mostly through the natural process, is an activity in ______________ sector.
(i) primary
(ii) secondary
(iii) tertiary
(iv) information technology

(c) GDP is the total value of _____________ produced during a particular year.
(i) all goods and services
(ii) all final goods and services
(iii) all intermediate goods and services
(iv) all intermediate and final goods and services

(d) In terms of GDP the share of tertiary sector in 2003 is _________
(i) between 20 per cent to 30 per cent
(ii) between 30 per cent to 40 per cent
(iii) between 50 per cent to 60 per cent
(iv) 70 per cent

Answer:
(a) (iii)
(b) (i)
(c) (ii)
(d) (iii)

More Resources for CBSE Class 10

Q4: Find the odd one out and say why.
Answer:

Tourist guide, dhobi, tailor, potter.
Teacher, doctor, vegetable vendor, lawyer.
Postman, cobbler, soldier, police constable.
MTNL, Indian Railways, Air India, Sahara Airlines, All India Radio.
Potter, because only the potter relates to the secondary sector.
Vegetable vendor, since only this directly helps in the production of goods.
Cobbler because the only cobbler falls in the private sector.
Sahara Airlines, as this is only a private sector company in the group.

Q6: Do you think the classification of economic activities into primary, tertiary, and secondary is useful? Explain how.
Answer:
The classification of economic activities into primary, secondary, and tertiary sectors is helpful as mentioned below :

It provides information on how and where the people of a country are employed. For example in India in 2000, the share of the primary sector in employment was about 60 percent e., more than other sectors.
It also helps in ascertaining as to which sector of economic activity contributes more or less to the country’s GDP and per capita income.
If the tertiary sector is developing much faster than the primary sector, then it implies that agriculture is depleting and the government must take measures to rectify this.
The knowledge that the agricultural profession is becoming unpopular or regressive can only come if we know which sector it belongs to.
It provides us information about employment conditions in different sectors. For example in India, the primary sector faces the problem of disguised unemployment. In this sector, more people are employed and even if some are removed, production will not be affected.
It provides us the information about progress in different sectors. For example, the importance of the tertiary sector has increased due to various factors need for basic services and the coming of IT services.
In view of the above factors, it is necessary to classify economic activities into three sectors for smooth economic administration and development.

Q7: For each of the following sectors that we came across in this chapter why should one focus on employment and GDP? Could there be other issues which should be examined? Discuss.
Answer:
(1) For each of the sectors we focus on employment and GDP due to the reasons mentioned below :

To know the number of people employed in that sector. For example in 2000, the share of the primary sector in employment was more than secondary and tertiary sectors.
To know the share of each sector in the GDP. For example in 2000, the share of the tertiary sector was more than that of the agriculture sector and secondary sector in the GDP.

By focusing on GDP and employment we can draw conclusions regarding the generation of new employment opportunities in various sectors and take necessary steps accordingly.
We come to know employment conditions for workers such as in the unorganized sector and take necessary steps to improve their condition. So that the workers are not exploited.

(2) Focus should be laid on other issues such as conditions of work, profit motive, efficiency, public welfare, environmentally friendly.

Conditions of work should be in the favour of workers.
The employment should be regular and the employer should follow various laws such as Factories Act, Minimum Wages Act etc.
The production must be for the welfare of the people who should not be exploited by raising prices or creating a scarcity of goods in the market. Thus, such issues must be examined while discussing the role of different sectors in the economy of the country.

Q9: How is the tertiary sector different from other sectors? Illustrate with few examples.
Answer:
The tertiary sector is different from other sectors as mentioned below :

The activities of the tertiary sector help in the development of primary and secondary sectors.
These activities, by themselves, do not produce a good, but they are an aid or support for the production process. For example, the transport system helps in taking goods from the factory to markets for the purpose of selling or storing in godowns.
It provides telephones and other products for communication to the traders. Banks provide money to help production and trade.
Thus transport, storage, communication etc. are not tertiary activities. On the other hand, primary sector forms the base for all products that we subsequently make. Minerals and ores are natural products which are converted into other forms by manufacturing. Sugar is made from sugarcane.

Q10: What do you understand by disguised unemployment? Explain with an example each from the urban and rural areas.
Answer: Disguised Unemployment is a kind of unemployment in which there are people who are visibly employed but are actually unemployed. This situation is also known as Hidden Unemployment. In such a situation more people are engaged in a work than required.

For example in rural areas, this type of unemployment is generally found in the agricultural sector like – in a family of 9 people all are engaged in the same agricultural plot. But if 4 people are withdrawn from it there will be no reduction in output. So, these 4 people are actually disguisedly employed.

In urban areas, this type of unemployment can be seen mostly in service sectors such as in a family all members are engaged in one petty shop or a small business which can be managed by less number of persons.

Q11: Distinguish between open unemployment and disguised unemployment.
Open Unemployment – When a country’s labour force do not get opportunities fro adequate employment, this situation is called open unemployment. This type of unemployment is generally found in the industrial sector of our country. This is also found among the landless agricultural labourers in rural areas.
Disguised Unemployment – This is a kind of unemployment in which there are people who are visibly employed but actually they don’t have full employment. In such a situation more people are engaged in a work than required. This type of unemployment is generally found in unorganized sector where either work is not constantly available or too many people are employed for the same work that does not require so many hands.

Q12: Tertiary sector is not playing any significant role in the development of Indian economy. Do you agree/ Give reasons in support of your answer?
Answer:
“The tertiary sector is not playing any significant role in the development of Indian economy” is partially correct due to reasons as mentioned below :

The share of tertiary sector in employment has not increased in proportion to its increase in production. In 2000, the production in service sector rose by 11 times, whereas employment has risen less than three times. Therefore, still more than half of the workers in the country are working in the primary sector.

New services such as based on information technology have become important, but not all the services of the service sector are growing well. At one end are highly skilled and educated workers but on the other end, there are a very large number of workers engaged in services such as small shopkeepers, repair Arsons, transport persons. These persons barely manage to earn a living and yet they perform these services because no alternative opportunities for work are available to them. Such persons can not play any important role in the development of the Indian economy. It is this part of service sector that is not growing in importance.

Q13: Service sector in India employs two different kinds of people. Who are these?
Answer:
The service sector in India employs the following two different kinds of people. They are:
(a) The people involved in the services that may directly help in the production of goods. For example, people involved in the transportation, storage, communication, finance etc.
(b) The people involved in such services that may not directly help in the production of goods e.g. teachers, doctors, barbers, cobblers lawyers etc. They may be termed as ancillary workers means those who give services to the primary service providers.

Q14: Workers are exploited in the unorganized sector. Do you agree with this view.? Give reasons in support of your answer.
Answer:
Yes, workers are exploited in the unorganized sector. This would be clear from the following points:

There is no fixed number of working hours. The workers normally work 10 – 12 hours without paid overtime.
They do not get other allowances apart fro the daily wages.
Government rules and regulations to protect the labourers are not followed there.
There is no job security.
Jobs are low paid the workers in this sector are generally illiterate, ignorant and unorganized. So they are not in a position to bargain or secure good wages.
Being very poor they are always heavily in debt. So, they can be easily made to accept lower wages.

Q15: How are the activities in the economy classified on the basis of employment conditions?
Answer:
On the basis of employment conditions, the activities in the economy are classified into organized and unorganized sectors.

Organized Sector This sector covers those enterprises which are registered by the government and have to follow its rules and regulations. For example, Reliance Industries Ltd., GAIL etc.

Unorganized Sector It includes those small and scattered units which are largely outside the control of the government. Though there are rules and regulations but these are never followed here. For example, casual workers in construction, shops etc. In this sector there is no job security and the conditions of employment are also very tough.

Q16: Compare the employment conditions prevailing in the organised and unorganised sectors.
Answer:
The employment conditions prevailing in the organised and unorganised sectors are vastly different. The organised sector has companies registered with the government and hence, it offers job security, paid holidays, pensions, health and other benefits, fixed working hours and extra pay for overtime work. On the other hand, the unorganised sector is a host of opposites. There is no job security, no paid holidays or pensions on retirement, no benefits of provident fund or health insurance, unfixed working hours and no guarantee of safe work environment.

Q17: Explain the objective of implementing the NREGA 2005.
Answer:

The objective of implementing the NREGA 2005 i.e., National Rural Employment Guarantee Act 2005 is to implement the right to work.
The Act has to be implemented in 200 districts.
Under this Act, all those who are able to, and are in need of work have been guaranteed 100 days of employment in a year by the government.
If the government fails in its duty to provide employment, it will give unemployment allowance to the people.
The types of work that would in future help to increase the production from land will be given preference under this Act.

Q18: Using examples from your area compare and contrast the activities and functions of private and public sectors.
Answer:
The activities and functions of private and public sectors in our area may be compared as mentioned below :

Private Sector	Public Sector
(1) The vegetable shops, grocery shops, sweet shops etc. are in private sector.	(1) Mother Dairy booths which sell vegetables, fruits, milk and milk products are in public sector.
(2) These are owned by private individuals.	(2) These are owned by public sector undertaking ‘Mother Dairy’
(3) Vegetables and other products are generally of good quality.	(3) The vegetables and fruits are generally of average or poor quality.
(4) The rates may be slightly higher	(4) The rates are lower than the market rates.
(5) The companies like Reliance, Tata, Airtel provide telephone and TV services which are of very good standard.	(5) MTNL provides telephone services. There are complaints against their services. On many occasions, telephones remain out of order, hut they do not charge for that period.
(6) The shopkeepers provide free home delivery service without any extra-charge.	(6) Mother Dairy or any other public under taking do not provide free home delivery service.
(7) Private schools provide education of good quality. Their students are well-dressed and disciplined. Their medium of in structions is always English.	(7) The schools run by MCD do not provide quality education. Their students are not well-dressed and disciplined. Their medium of instructions is generally Hindi.

Q20: Give three examples of Public Sector activities and explain why the government has taken up them.
Answer: The examples are:
Railways: The government has taken up it for the following reasons –
1. Only the government can invest large sums of money on the public project with long gestation period.
2. To ensure and provide transportation at cheap rate.
NTPC: The government has taken up it to provide electricity at a lower rate than the actual cost of production. The aim is to protect and encourage the private sector especially small scale industries.
AIIMS: To provide quality health services at reasonably cheap rate was the main purpose of the government to start this.

Q21: Explain how Public sector contributes to the economic development of a nation.
Answer: In the following ways Public sector contributes to the economic development of a nation:

It promotes rapid economic development through creation and expansion of infrastructure.
It creates employment opportunities.
It generates financial resources for development.
It is ensuring equality of income, wealth and thus, a balanced regional development.
It encourages development of small, medium and cottage industries.
It ensures easy availability of goods at moderate rates.
Contributes to community development i.e. to the Human Development Index (HDI) via health and educational services.

Q22: The workers in the unorganised sector need protection on the following issues: wages, safety and health. Explain with examples?
Answer:
The workers in the unorganised sector need protection on the following issues: wages, safety and health. In the construction sector, labourers are employed on a daily basis. Hence, they have no job security. Here, wages too differ from time to time. Consequently, the government has set up a minimum wages act to protect such workers from economic exploitation.

The same problem exists for miners working in private mining companies. Their safety is secondary to the company’s profits, and as a result, many miners suffer grievous injuries (and many a times, even die) due to inadequate safety gear and norms. Governments of most nations have now laid down strict rules for private enterprises to ensure workers’ safety.

Most companies in the unorganised sector do not provide health insurance to their employees. Some of these might be involved in dangerous factory production that may harm a worker’s health in the long term. These workers need to be protected against the tyranny of the employer, and it is here that the government steps in.

Q23: A study in Ahmedabad found that out of 15,00,000 workers in the city, 11,00,000 worked in the unorganised sector. The total income of the city in this year (1997-1998) was Rs 60,000 million. Out of this Rs 32,000 million was generated in the organised sector. Present this data as a table. What kind of ways should be thought of for generating more employment in the city?
Answer:
Ways to generate more employment in the city of Ahmedabad have to be provided by the government, especially in the unorganised sector. As the table shows, the organised sector’s earnings are much higher than that of the unorganised sector even though the latter employs almost 80% of the city workers. More companies need to be brought under the roof of the organised sector so that workers from the unorganised sector are attracted to jobs there, with higher and more secure wages. For this, the government must provide loans and aid to companies transferring from unorganised to organised sectors.

Multiple Choice Questions

Previous Years’ Questions
1. The sectors are classified into public and private sector on the basis of: [CBSE (CCE) 2011]
(a) Employment conditions
(b) The nature of economic activities
(c) Number of workers employed
(d) Ownership of enterprises

2. The value of all final goods and services produced within a country during a particular year is called as: [CBSE (CCE) 2011]
(a) Gross Domestic Product
(b) Net Domestic Product
(c) National Product
(d) Production of Tertiary Sector

3. The service sector includes activities such as [CBSE(CCE)2011]
(a) agriculture, dairy, fishing and forestry
(b) making sugar, gur and bricks
(c) transport, communication and banking
(d) None of these

4. Choose the correct meaning of organised sector [CBSE (CCE) 2011]
(a) It covers those enterprises where the terms of employment are regular.
(b) It is outside the control of the government.
(c) Jobs are not regular.
(d) It provides low salaries.

NCERT Questions
5. Production of a commodity, mostly through the natural process, is an activity in sector.
(a) primary
(b) secondary
(c) tertiary
(d) information technology

6. GDP is the total value of ………….. produced during a particular year.
(a) all goods and services
(b) all final goods and services
(c) all intermediate goods and services
(d) all intermediate and final goods and services

7. In terms of GDP the share of tertiary sector in 2003 is:
(a) between 20 per cent to 30 per cent
(b) between 30 per cent to 40 per cent
(c) between 50 per cent to 60 per cent
(d) 70 per cent

Additional Questions
8. Underemployment occurs when people
(a) do not want to work
(b) are working in a lazy manner
(c) are working less than what they are capable of doing
(d) are not paid for their work

9. When we produce a good by exploiting natural resources, it is an activity of the
(a) Secondary sector
(b) Tertiary sector
(c) Primary sector
(d) Organised sector

10. Natural products are changed into other forms through ways of manufacturing
(a) Primary sector
(b) Secondary sector
(c) Tertiary sector
(d) Unorganised sector

11. Which of the following is included in tertiary sector?
(a) ATM booths
(b) Call centres
(c) Internet cafe
(d) All of them

12. Only ………… are included to know the total production in each sector.
(a) Final goods and services
(b) Intermediate goods
(c) Only goods
(d) Only services

13. At the initial stages of development, ………………. was the most important sector of economic activity
(a) Primary sector
(b) Secondary sector
(c) Tertiary sector
(d) Organised sector

14. In the past 100 years, there has been a further shift from secondary to ……………. in developed countries.
(a) Primary sector
(b) Organised sector
(c) Tertiary sector
(d) Unorganised sector

15. Mention the largest producing sector in 2003 in India ?
(a) Primary
(b) Secondary
(c) Tertiary
(d) Unorganised sector

16. Name the sector which continues to be the largest employer even in the year 2000.
(a) Secondary
(b) Primary
(c) Tertiary
(d) Banking section

17. A situation in which more persons are employed on a job than are optimally required.
(a) Structural unemployment
(b) Disguised unemployment
(c) Cyclical unemployment
(d) Seasonal unemployment

18. A study conducted by the planning commission estimates that the following number of jobs can be created in the education sector alone.
(a) 20 lakhs
(b) 15 lakhs
(c) 18 lakhs
(d) 25 lakhs

19. Out of 200 million children in the school going age group, how many are attending schools?
(a) One – fourth
(b) Half
(c) Two – thirds
(d) One – fifth

20. According to planning commission, if tourism as a sector is improved, every year we can give additional employment to people more than
(a) 25 lakhs
(b) 30 lakhs
(c) 32 lakhs
(d) 35 lakhs

21. Central government in India made a law, implementing the Right to Work in how many districts of India ?
(a) 150 districts
(b) 200 districts
(c) 250 districts
(d) 300 districts

22. Under NREGA 2005, how many days of work, in a year are guaranteed by the government?
(a) 100 days
(b) 120 days
(c) 90 days
(d) 99 days

23. Enterprises or places of work where the terms of employment are regular and people have assured work comes under
(a) Primary sector
(b) Organised sector
(c) Unorganised sector
(d) Tertiary sector

24. Percentage of people in the unorganised sector in tertiary sector is …………………..
(a) 67 %
(b) 76 %
(c) 51 %
(d) 75 %

25. In the rural areas, the unorganised sector mostly comprises of
(i) Landless agricultural labourers
(ii) Garment makers
(iii) Street vendors
(iv) Sharecroppers and artisans
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)

26. Which of them does not generally find itself in the unorganised sector ?
(a) Scheduled castes
(b) Scheduled tribes
(c) Rich families
(d) Backward communities

27. Government owns most of the assets and provides all the.services
(a) Private Sector
(b) Public Sector
(c) Organised Sector
(d) Tertiary Sector

28. There are large number of activities like providing health and education which are the primary responsibility of
(a) Primary sector
(b) Private companies
(c) Government
(d) Secondary sector

ANSWERS

NCERT Solutions for Class 10 Social Economics Chapter 4 Globalisation and the Indian Economy

May 20, 2022

Formulae Handbook for Class 10 Maths and Science

NCERT Solutions for Class 10 Social Economics Chapter 4 Globalisation and the Indian Economy

Listen to Audio Solutions for Globalisation and the Indian Economy

Page 72:
Question 1: What do you understand by globalisation? Explain in your own words.
Answer:

Globalization is a process of interaction and integration among the people, companies, and governments of different nations, a process driven by international trade and investment and aided by information technology.
Under globalization the countries that hitherto closed to trade and foreign investment open up their economies and go global. The result is increasing interconnectedness and integration of the economies of the world.
Under globalization more and more goods and services, investments and technology are moving between countries.
In addition to goods, services, investments, and technology, there is a movement of people who move from one country to another in search of better income, better jobs or better education.

Question 2: What was the reason for putting barriers to foreign trade and foreign investment by the Indian government? Why did it wish to remove these barriers?
Answer:
(1) The government had put restrictions on the import of goods to protect domestic producers from foreign competition because industries were coming up in the 1950s and 1960s, and competition from imports at that stage would not have allowed these industries to come up. Thus, the government allowed imports of only essential items such as machinery, fertilizers, and petroleum. These restrictions helped to attain technological capability within the country.

(2) Starting around 1991, the government wished to remove the barriers due to reasons as mentioned below :

India had attained technological capability.
The government decided that the time had come for Indian producers to compete with producers around the globe.
It felt that competition would improve the performance of producers within the country since they would have to improve their quality.
There would be an unrestricted exchange of capital, technology, and experience between India and other countries of the world.

Thus, barriers to foreign trade and foreign investment were removed. Now goods could be imported and exported easily. The government reduced taxes on imported goods, and encouraged investors from abroad to invest in India.

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Question 3: How would flexibility in labour laws help companies?
Answer:
Flexibility in labour laws will help companies in being competitive and progressive. By easing up on labour laws, company heads can negotiate wages and terminate employment, depending on market conditions. This will lead to an increase in the company’s competitiveness.

Question 4: What are the various ways in which MNCs set up, or control, production in other countries?
Answer:
MNCs set up, or control, production in other countries in the following ways :

MNCs set up production on the basis of the following factors :
- Closeness of the place to the markets.
- Availability of skilled and unskilled labour at low costs.
- Availability of other factors of production e., raw material, etc.
- Government’s favourable policies.
After assuring above conditions, MNCs set up factories and offices for production. They buy assets such as land, buildings, machines and other equipment.
At times MNCs set up production jointly with local companies because the local company has knowledge of the local business conditions. Moreover the domestic company has an established framework of business. MNCs provide money and latest technology for production.
MNCs buy up local companies to expand production. MNCs with huge wealth can quite easily do so.
Some MNCs start as an independent entity right from the beginning.
While some of the MNCs produce entirely for the local market, many others produce for the exports markets.
MNCs in developed countries place orders for production with small producers of developing countries for various products such as garments, footwear. These products are supplied to the MNCs which sell them under their own brand names to the customers. The MNCs decide their price, quality, delivery, and labour conditions for these distant producers.

Thus we see that there are a variety of ways in which MNCs are spreading their production and interacting with local producers in various countries across the globe. As a result, production in these widely dispersed locations is getting interlinked.

Question 5: Why do developed countries want developing countries to liberalise their trade and investment? What do you think should the developing countries demand in return?
Answer:
Developed countries want developing countries to liberalise their trade and investment because then the MNCs belonging to the developed countries can set up factories in less-expensive developing nations, and thereby increase profits, with lower manufacturing costs and the same sale price. In my opinion, the developing countries should demand, in return, for some manner of protection of domestic producers against competition from imports. Also, charges should be levied on MNCs looking to set base in developing nations.

Question 6: “The impact of globalisation has not been uniform.” Explain this statement.
Answer:
The impact of globalisation has not been uniform as explained below :
(1) Positive impact :

Globalization has resulted in more choices for the consumers who now get better quality and at lower prices several products.
This has improved the standard of living of people, particularly living in urban areas.
MNCs have increased their investments in developing countries like India in industries such as cell-phones, automobiles, electronics, soft drinks, etc. As a result of it new jobs have been created in developing countries.
Some local companies that supply raw materials to MNCs have also benefited.
Some local companies in countries like India have been able to invest in newer technology and production methods. They are successful in raising their production standards.
Globalisation has enabled some large companies such as Tata Motors, Infosys to emerge as multi-national companies.
Companies providing services particularly in the field of information and communication technologies have also benefited by globalisation. Similar is the case in services like data entry, accounting, administrative tasks and engineering.

(2) Negative impact: The impact of globalisation has been harmful too as mentioned below :

Creation of special economic zones has disrupted the lives of people who are displaced such as tribals. Sometimes to produce more electricity dams are constructed and their land is submerged and the people are left without any job.
Flexibility in labour laws: Flexibility in labour laws is allowed by the government to attract foreign investment. This has resulted in worsening the condition of workers because they are appointed on a temporary basis to avoid payment of provident fund and other facilities. No overtime is paid for extra hours of work. The workers are paid low wages.
Effect on small producers: Globalisation has hit the small producers because they are unable to compete with MNCs or the big producers or manufacturers. Several units have been shut down rendering many workers jobless. In India, small industries which employ about 20 million workers have been hit adversely.
From above description, it is clear that the impact of globalisation has not been uniform. It has positive as well as a negative impact.

Question 7: How has liberalisation of trade and investment policies helped the globalisation process?
Answer: Liberalisation of trade and investment policies has helped the globalisation process by making foreign trade and investment easier. Earlier, several developing countries had placed barriers and restrictions on imports and investments from abroad to protect domestic production. However, to improve the quality of domestic goods, these countries have removed the barriers. Thus, liberalisation has led to a further spread of globalisation because now businesses are allowed to make their own decisions on imports and exports. This has led to a deeper integration of national economies into one conglomerate whole.

Question 8: How does foreign trade lead to the integration of markets across countries? Explain with an example other than those given here.
Answer:

Foreign trade leads to the integration of markets across countries because it creates an opportunity for the producers to reach beyond the domestic markets i.e., markets of their own countries. Producers can sell their products in the markets of their own country as well as in other countries all over the world. They can also compete in markets located in other countries of the world.
The buyers too have a choice between the goods produced in different parts of the world. It enables the consumer to buy according to his requirement.
The competition among the producers bring them closer to each other.
Sometimes the producers of other countries set up joint ventures as AIG have set up joint venture in insurance sector and are selling their products in India.
Thus in general, with the opening of trade, goods travel from one market to another. Prices of similar goods in two markets tend to become equal. And producers in the two countries now closely compete against each other even though they are separated by thousands of miles. Foreign trade, thus, results in connecting the markets or integration of markets in different countries.

Question 9: Globalisation will continue in the future. Can you imagine what the world would be like twenty years from now? Give reasons for your answer.
Answer: Globalisation will continue in the future. Twenty years from now, the world will be more globally connected and integrated into one international economy, if this process continues on a fair and equitable basis. Trade and capital flows will increase alongside the mobility of labour. This will occur because liberalisation will get augmented and MNCs will converge with other companies producing the same goods.

Question 10: Supposing you find two people arguing: One is saying globalisation has hurt our country’s development. The other is telling, globalisation is helping India develop. How would you respond to these organisations?
Answer:
Both the arguments have some truth as mentioned below :
Globalisation has helped India develop as mentioned below :

Many MNCs are making an investment in India in different sectors like insurance banking and food processing.
These investments have benefited people in a, number of ways which has resulted in the development of the country.
Now people have choices. They can buy anything of their choice costly or cheap.
People are getting jobs with a handsome salary.
The living standard of people has increased.
Many projects are going on with the help of foreign investment. Different states are making efforts to attract foreign companies to make an investment in their states and are successful in their mission.

The globalisation, however, has hurt the country’s development as mentioned below :

For a large number of small producers globalisation has posed many challenges. Batteries, capacitors, plastics toys, tires, dairy products and vegetable oil industries have been hit badly due to competition.
Many small units have been shut down rendering many workers jobless.
As the small industries in India employ the largest number of workers (20 million) in the country, next only to agriculture, it has hurt the development.
Thus, both arguments have some truth in them. However, if steps are taken to have a fair globalization, then the adverse effects may be minimised and may not hurt the country’s development.

Question 11: Fill in the blanks.
Indian buyers have a greater choice of goods than they did two decades back. This is closely associated with the process of ______________. Markets in India are selling goods produced in many other countries. This means there is increasing ______________ with other countries. Moreover, the rising number of brands that we see in the markets might be produced by MNCs in India. MNCs are investing in India because _____________. While consumers have more choices in the market, the effect of rising _______________ and ______________has meant greater ________________among the producers.
Answer:
Indian buyers have a greater choice of goods than they did two decades back. This is closely associated with the process of globalisation. Markets in India are selling goods produced in many other countries. This means there is increasing trade with other countries. Moreover, the rising number of brands that we see in the markets might be produced by MNCs in India. MNCs are investing in India because of cheaper production costs. While consumers have more choices in the market, the effect of rising demand and purchasing power has meant greater competition among the producers.

Question 13: Choose the most appropriate option.
(i) The past two decades of globalisation has seen rapid movements in
(a) goods, services and people between countries.
(b) goods, services and investments between countries.
(c) goods, investments and people between countries.

(ii) The most common route for investments by MNCs in countries around the world is to
(a) set up new factories.
(b) buy existing local companies.
(c) form partnerships with local companies.

(iii) Globalisation has led to an improvement in living conditions
(a) of all the people
(b) of people in developed countries
(c) of workers in the developing countries
(d) none of the above
Answer:
(i) (b)
(ii) (b)
(iii) (d)

Multiple Choice Questions

1. Cargill foods is the largest producer of which of the following in India? [Delhi, 2012]
(a) Medicines
(b) Asian Paints
(c) Edible oil
(d) Garments

2. W.T.O. was started at the initiative of which one of the following group of countries? [Delhi, 2012]
(a) Rich countries
(b) Poor countries
(c) Developed countries
(d) Developing countries

3. Which one of the following organisations lays stress on liberalisation of foreign trade and foreign investment? [Delhi, 2012]
(a) International Labour Organisation
(b) International Monetary Fund
(c) World Health Organisation
(d) World Trade Organisation

4. Which one of the following is not characteristic of ‘Special Economic Zone’? [AI, 2012]
(a) They do not have to pay taxes for long period.
(b) Government has allowed flexibility in labour laws.
(c) They have world-class facilities.
(d) They do not have to pay taxes for an initial period of five years.

5. Which one of the following Indian industries has been hit hard by globalisation? [AI, 2012]
(a) IT
(b) Toymaking
(c) Jute
(d) Cement

6. Which one of the following type of countries has been more benefited from globalisation? [AI, 2012]
(a) Rich countries
(b) Poor countries
(c) Developing countries
(d) Developed countries

7. Removing barriers or restrictions set by the government is called: [CBSE (CCE) 2012]
(a) Liberalisation
(b) Investment
(c) Fovourable trade
(d) Free trade

8. Investment made by MNCs are termed as: [CBSE (CCE)2012]
(a) Indigenous investment
(b) Foreign investment
(c) Entrepreneur’s investment
(d) None of the above

9. What is the process of rapid integration or interconnection between countries called? [CBSE (CCE) 2012]
(a) Industrialization
(b) Globalization
(c) Liberalization
(d) Privatization

10. Which one of the following is an example of a trade barrier? [CBSE (CCE) 2012]
(a) Tax on Exports
(b) Tax on Imports
(c) Free Trade
(d) Restriction on Export

11. Removal of barriers set by the government is known as [CBSE(CCE)2012]
(a) Globalisation
(b) Liberalisation
(c) Industralisation
(d) Privatisation

12. Globalisation does NOT involve which one of the following? [Delhi 2011]
(a) Rapid integration between countries.
(b) More goods and services moving between countries.
(c) Increased taxes on imports.
(d) Movement of people between countries for jobs, education etc.

13. Which of the following is not a feature of a Multi-National Company? [AI 2011]
(a) It owns/controls production in more than one nation.
(b) It sets up factories where it is close to the markets.
(c) It organises production in complex ways.
(d) It employs labour only from its own country.

14. Liberalisation involves which one of the following? [Foreign 2011]
(a) Removal of trade barriers
(b) Increasing subsidy on fertilisers
(c) Increasing import duties on goods
(d) Increasing export duties on goods

15. The past two decades of globalisation has seen rapid movements in
(a) goods, services and people between countries.
(b) goods, services and investments between countries.
(c) goods, investments and people between countries.

16. The most common route for investments by MNCs in countries around the world is to
(a) set up new factories.
(b) buy existing local companies.
(c) form partnerships with local companies.

17. Globalisation has led to an improvement in living conditions
(a) of all the people
(b) of people in developed countries
(c) of workers in the developing countries
(d) none of the above.

18. Globalisation, by connecting countries, shall result in
(a) lesser competition among producers.
(b) greater competition among producers.
(c) no change in competition among producers.

Additional Questions

19. Company that owns or controls production in more than one nation
(a) Foreign companies
(b) Government companies
(c) Multinational companies
(d) Private companies

20 Investment made by MNCs is called
(a) Mutual investment
(b) Inter-government investment
(c) Portfolio Investment
(d) Foreign investment

21. Benefit to the local company of joint production with MNCs is
(i) Money from MNCs for additional investments
(ii) Moral and Social support
(iii) Latest technology for production
(iv) All of them
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iii)

22. Cargill Foods, a very large American MNC, has bought over smaller Indian companies such as
(a) Parakh Foods
(b) Amul
(c) Britannia
(d) None of the above

23. Cargill is now the largest producer of edible oil in India, with a capacity to make ………… pouches daily.
(a) 6 million
(b) 5 million
(c) 4 million
(d) 55 million

24. Examples of industries where production is carried out by a large number of small producers around the world
(a) Garments
(b) Footwear
(c) Sport items
(d) All of them

25. Ford motors came to India in
(a) 1996
(b) 1995
(c) 1994
(d) 1990

26. Effect of Chinese toys on Indian toymakers is
(a) No effect
(b) Making profits
(c) Suffering losses
(d) None of them

27. Rapid integration or interconnection between countries is known as
(a) Privatisation
(b) Globalisation
(c) Liberalisation
(d) Socialisation

28. Post 50 years have seen several improvements in
(a) Transportation technology
(b) Information technology
(c) Communication technology
(d) All of them

29. Tax on imports is an example of
(a) Terms of Trade
(b) Collateral
(c) Trade Barriers
(d) Foreign Trade

3B Removing barriers or restrictions set by the government is known as
(a) Privatisation
(b) Liberalisation
(c) Globalisation
(d) Socialisation

31. Around which year, need for removing barriers on foreign trade and foreign investment in India was felt ?
(a) 1990
(b) 1991
(c) 1992
(d) 2000
32. ……………. is one such organisation whose aim is to liberalise international trade
(a) UNICEF
(b) World Bank
(c) WTO
(d) IDBI

33. Till 2006, how many members were there in WTO?
(a) 139
(b) 150
(c) 101
(d) 149

34. Companies who set up production units in the Special Economic Zones (SEZs) do not have to pay taxes for an initial period of
(a) 2 years
(b) 5 years
(c) 4 years
(d) 10 years

35. Industries where small manufacturers have been hit hard due to competition.
(a) Batteries
(b) Tyres
(c) Dairy Products
(d) All of them

36. Number of workers that small industries in India employ
(a) 18 million
(b) 19 million
(c) 20 million
(d) 21 million

37. To get large orders, Indian exporters try hard to cut their own costs by
(a) Reducing cost of raw materials
(b) Reducing advertising and marketing cost
(c) Reducing electricity cost
(d) Cutting labour cost

38. To achieve the goal of fair globalisation, a major role can be played by
(i) People
(ii) Government
(iii) MNCs
(iv) None of the above
(a) (i) and (iii)
(b) (ii) and (iv)
(c) (i) and (ii)
(d) (iii) and (iv)

39. It refers to globalisation which creates opportunities for all and ensures that its benefits are better shared.
(a) Privatisation
(b) Special Economic Zones (SEZ)
(c) WTO
(d) Fair globalisation

40. Allowing private sector to set up more and more of such industries as were previously reserved for the public sector.
(a) Globalisation
(b) Privatisation
(c) Liberalisation
(d) Socialisation

ANSWERS

NCERT Solutions for Class 10 Social Economics Chapter 5 Consumer Rights

May 20, 2022

Formulae Handbook for Class 10 Maths and Science

NCERT Solutions for Class 10 Social Economics Chapter 5 Consumer Rights

Page 87
Question 1: Why are rules and regulations required in the marketplace? Illustrate with a few examples.
Answer:
Rules and regulations are required in the market place due to the following reasons :

The consumers are exploited by the shopkeepers and traders in different ways such as less weight or measurement, more price, adulterated and defective goods.
In case of a complaint regarding a good or service, the shopkeeper or trader tries to avoid any responsibility. The seller tries to shift all the responsibility onto the buyer as if the seller has no responsibility once a sale is completed.
Sometimes producers are few and powerful while the consumers purchase in small amounts and are scattered. Big companies with huge wealth manipulate the market in many ways.
At times false information is passed on through the media, and other sources to attract consumers. For example, a company for years sold powder milk for babies all over the world as the most scientific product claiming this to be better than mother’s milk. It took years of struggle before the company was forced to accept that it had been making false claims. Similarly a long battle was fought with the cigarette manufacturing companies to accept that their product could cause cancer. Hence there is a need for rules and regulations to ensure protection for consumers.

Question 2: What factors gave birth to the consumer movement in India? Trace its evolution?
Answer:
The factors that gave birth to the consumer movement in India are manifold. It started as a “social force” with the need to protect and promote consumer interests against unfair and unethical trade practices. Extreme food shortages, hoarding, black marketing and adulteration of food led to the consumer movement becoming an organised arena in the 1960s. Till the 1970s, consumer organisations were mostly busy writing articles and holding exhibitions.

More recently, there has been an upsurge in the number of consumer groups who have shown concern towards ration shop malpractices and overcrowding of public transport vehicles. In 1986, the Indian government enacted the Consumer Protection Act, also known as COPRA. This was a major step in the consumer movement in India.

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Question 3: Explain the need for consumer consciousness by giving two examples.
Answer:
Two examples are Reji’s suffering and Amritha’s waiting. In case of Reji, a hospital, due to negligence of the doctors and staff in giving anaesthesia, crippled him for life. In case of Amritha, an engineering graduate, after attending an interview for job, did not receive any news of the result. In both the cases, they were conscious of their rights. Reji’s father filed a complaint in the State Consumer Disputes Redressal Commission claiming compensation of ? 5 lakh for medical negligence and deficiency in service.

The State Commission dismissed his case but he appealed again in the National Consumer Disputes Redressal Commission, New Delhi. The National Commission in its decision held hospital responsible for medical negligence and directed to pay the compensation. In case of Amritha, she filed an application under RTI Act to know the result. She soon got her call letter for appointment. Thus, there is a need for consumer consciousness to protect their interests successfully.

Question 4: Mention a few factors which cause the exploitation of consumers.
Answer: Exploitation of consumers is caused by a variety of factors. Producers are always looking for easy ways to increase profits. Adulterated or low-quality goods have fewer production costs, and if the consumer is unaware or illiterate, it is easy to cheat him/her. Also, shopkeepers brush off their responsibility by claiming that the manufacturer is to blame. Consumers feel helpless in this situation. Often, when the consumers are known not to check the retail price of a commodity on its packing, sellers add extra charges to the same. In places where there is no awareness of consumer rights and the COPRA, consumer exploitation is rampant.

Question 5: What is the rationale behind the enactment of Consumer Protection Act 1986?
Answer:
The rationale behind the enactment of Consumer Protection Act 1986 (COPRA) was to protect the interests of the consumers because there are no legal formalities for filing the complaint. A consumer need not employ a lawyer or professional for legal assistance. He himself can plead the case in a consumer court. A person can make a complaint to consumer court on a plain paper along with supporting documents such as guarantee or warrantee card, cash memo etc.

Question 6: Describe some of your duties as consumers if you visit a shopping complex in your locality.
Answer:
Some of my duties as a consumer if I visit a shopping complex include checking expiry dates of the products I wish to purchase, paying only the maximum retail price printed on the goods, preventing shopkeepers from duping me with defective products, and registering a complaint with a consumer forum or court in case a seller refuses to take responsibility for an adulterated or flawed product.

Question 7: Suppose you buy a bottle of honey and a biscuit packet. Which logo or mark you will have to look for and why?
Answer:
While buying a bottle of honey or a biscuit packet, the logo or mark one will have to look for is ISI or Agmark. These are logos certifying the quality of goods in the market. Only those producers are allowed to use these marks who follow certain quality standards set by the organisations issuing these certifications. Thus, if a bottle of honey or a biscuit packet has one of these logos on it, then it implies that the product is of good quality.

Question 8: What legal measures were taken by the government to empower the consumers in India?
Answer:
The following legal measures were taken by the government to strengthen the consumers in India :

Consumer Protection Act popularly known as COPRA was enacted in 1986. It was amended in 1991 and 1993.
In October 2005, Right to Information Act was enacted. This enables citizens to have all the information about the functions of government departments. The citizens have the right to know the particulars of goods and services they purchase.

Question 9: Mention some of the rights of consumers and write a few sentences on each?
Answer:
Some of the rights of consumers include the right to be informed, the right to choose, the right to seek redressal and the right to representation in consumer courts. Under the RTI Act of 2005, consumers can now even get information regarding the working of government departments. The right to choose allows a consumer to choose if he wishes to continue or discontinue the use of a service he purchased. The right to seek redressal permits a consumer to complain against unfair trade practices and exploitation.

Question 10: By what means can the consumers express their solidarity?
Answer:
The consumers can express their solidarity by forming consumer awareness organisation which may get representation in various committees formed by the government. There should be consumer’s active involvement to protect the interest of all the consumers.

Question 11: Critically examine the progress of the consumer movement in India?
Answer:
The consumer movement in India has evolved vastly since it began. There has been a significant change in consumer awareness in the country. Till the enactment of COPRA in 1986, the consumer movement did not bear much force, but ever since its inception, the movement has been empowered substantially. The setting up of consumer courts and consumer groups has been a progressive move. However, in contemporary India, the consumer redressal process is quite complicated, expensive and time-consuming. Filing cases, attending court proceedings, hiring lawyers, and other procedures make it cumbersome. In India, there are over 700 consumer groups of which, unfortunately, only about 20-25 are well-organized and functioning smoothly.

Question 13: Say True or False.

COPRA applies only to goods.
India is one of the many countries in the world which has exclusive courts for consumer redressal.
When a consumer feels that he has been exploited, he must file a case in the District Consumer Court.
It is worthwhile to move to consumer courts only if the damages incurred are of high value.
Hallmark is the certification maintained for standardisation of jewellry.
The consumer redressal process is very simple and quick.
A consumer has the right to get compensation depending on the degree of the damage.

Answer:

False
True
True
True
True
False
True

Multiple Choice Questions

1. Which one of the following logos is used for standardisation of agricultural products? [Delhi, 2012]
(a) I.S.I
(b) Hallmark
(c) Agmark
(d) ISO

2. In which one of the following courts a consumer should file a case if he/she is exploited in the market? [Delhi, 2012]
(a) Local court
(b) State court
(c) Supreme court
(d) Consumer court

3. Hallmark is used as a logo for which one of the following? [AI, 2012]
(a) Agricultural products
(b) Jewellery
(c) Electrical goods
(d) Electronic goods

4. On which one of the following items is I.S.I. used as a logo? [Foreign, 2012]
(a) LPG Cylinder
(b) Jewellery
(c) Gold
(d) Agricultural products

5. For which of these products does it become mandatory for the producer to get certified? [CBSE CCE 2012]
(a) Fruits
(b) Telephones
(c) LPG Cylinders
(d) Cigarettes

6. The district court deals with the cases involving claim up to ………….. [CBSE (CCE) 2012]
(a) ₹ 1 crore
(b) ₹ 40 lakhs
(c) ₹ 30 lakhs
(d) ₹ 20 lakhs

7. The district level consumer court deals with the cares involving claims [CBSE (CCE) 2012]
(a) upto 20 lakhs
(b) upto 15 lakhs
(c) upto 1 crore
(d) upto 25 lakhs

8. Which of the following rights related to availing details of ingredients of a product? [CBSE (CCE) 2012]
(a) Right to safety
(b) Right to choose
(c) Right to be informed
(d) Right to represent

9. In which one of the following years was the Right to Information Act Implemented? [CBSE (CCE) 2012]
(a) 2004
(b) 2005
(c) 2006
(d) 2007

10. The district level court deals with the cases involving claims: [Delhi 2011]
(a) upto ₹10 lakhs
(b) upto ₹20 lakhs
(c) between ₹20 lakhs to ₹1 crore
(d) exceeding ₹1 crore

11. When did the United Nations adopt the guidelines for consumer protection? [AI 2011]
(a) 1983
(b) 1984
(c) 1985
(d) 1986

12. Which one of the following statements is false? [Foreign 2011]
(a) The consumer has a right to represent in the Consumer Court.
(b) The consumer redressal process is very simple and very quick.
(c) Hallmark is the certification maintained for standardisation of jewellery.
(d) The consumer has the right to be informed.

13. In the market place rules and regulations are required for the protection of the
(a) Sellers
(b) Suppliers
(c) Consumers
(d) Owners

14. In India, the consumer movement as a ……………….. originated with the necessity of protecting and promoting the interests of consumers against unethical and unfair trade practices.
(a) Cultural force
(b) Social force
(c) Economic force
(d) Political force

15. Rampant food shortages, hoarding, black marketing gave birth to the consumer movement in an organized form in the year
(a) 1947s
(b) 1970s
(c) 1960s
(d) 1965s

16. At International level, this has become the foundation for the consumer movement
(a) Consumers International
(b) COPRA
(c) Consumers Forum
(d) None of the above

17. A major step taken in 1986 by the Indian government was the enactment of
(a) RTI Act
(b) Consumer Protection Act.
(c) Consumer Movement
(d) Consumer Courts

18. In case of Reji Mathew, he suffered due to improper anesthesia which resulted in brain abnormalities. Who was held responsible by the National Commission after locking into a complaint ?
(a) Father
(b) Mother
(c) Hospital
(d) Patient himself

19. Because of this right, rules have been made so that the manufacturer displays all the information relating to the commodity
(a) Right to choose
(b) Right to be heard
(c) Right to seek redressal
(d) Right to be informed

20. In October 2005, the Government of India enacted a law known as
(a) Right to Choose Act
(b) Right to Information Act.
(c) COPRA
(d) Public Distribution System

21. A student who has paid lumpsum fee for course of three years to a coaching institute, now decides in between to discontinue that institute due to lack of quality of teaching. Can this student get a proportionate amount of fee refunded as per the law?
(a) No
(b) Yes
(c) May or May Not
(d) None of them

22. Consumers have the right to be protected against any danger caused by goods like electrical goods and pressure cookers. The right referred here is
(a) Right to seek redressal
(b) Right to be heard
(c) Right to safety
(d) Right to consumer education

23. Manufacturer should not use aggressive selling techniques to sell a particular product without giving the consumer a chance to select from alternative products available. Which right is mentioned here?
(a) Right to safety
(b) Right to choose
(c) Right to heard
(d) Right to be informed

24. Which right of consumer is violated if the consumers are not allowed to get their claims settled against the manufacturer in case they are cheated or exploited?
(a) Right to seek redressal
(b) Right to choose
(c) Right to be heard
(d) None of them

25. Consumer movement in India has led to the formation of various organizations locally known as
(a) Consumer Protection Council
(b) COPRA
(c) Resident Welfare Association (RWA)
(d) None of them

26. Consumer Forums guide consumers on how to file cases and represent individual consumers in the consumer court. Is this statement true?
(a) No
(b) May or May Not
(c) Yes
(d) Never

27. Under COPRA, a ……………. quasi-judicial machinery was set up for redressal of consumer disputes.
(a) Two-tier
(b) Three-tier
(c) Four-tier
(d) Five-tier

28. State-level court deals with the cases involving claims between
(a) ₹ 1 to 20 lakhs
(b) ₹ 1 Crore and above
(c) ₹ 20 lakhs to ₹ 1 Crore
(d) Any amount

29. Logos and certification which help consumers get assured of quality while purchasing the goods and devices are
(a) ISI
(b) Agmark
(c) Hallmark
(d) All of them

30. National Consumers’ Day in India is observed on
(a) 24 December
(b) 14 December
(c) 14 January
(d) 31 December

31. World Consumers Rights Day is celebrated on
(a) Jan 15
(b) Feb 15
(c) March 15
(d) Jan 1

32. The organization which sets standards of products at the International level
(a) ISO
(b) COPRA
(c) Agmark
(d) BIS

33. Organisation which sets International food standards
(a) Consumer International
(b) Codex Alimentarius Commission
(c) ISO
(d) COPRA

ANSWERS

NCERT Solutions for Class 10 Foundation of Information Technology – Inserting Images and Links in HTML

May 20, 2022

NCERT Solutions for Class 10 Foundation of Information Technology – Inserting Images and Links in HTML

Very Short Answer Type Questions [1 Mark each]

Question 1. How can text be displayed in place of image for users whose browser do not support images? CBSE 2007
Answer: The alt attribute of <img> tag is used to display the text in place of image for the users whose browser do not support images.

Question 2. Write a statement in HTML that inserts an image named ‘school.jpg’ found in the ‘images’ folder of the current folder. In case the image cannot be found, it should display ‘Schools in India’.
Answer: <img src =”images\school.jpg” alt=”Schools in India”>

More Resources for CBSE Class 10

Question 3. The following code is written to align the image in center in the browser’s window.
However, the>desired result is not achieved. Mention the reason.
<img src = “image.jpg” align = “center”>
Answer: The reason for not getting the desired result is that center is not a value of align attribute in <img> tag.

Question 4. Why width and height attributes are used?
Answer: The width and height attributes are used, such that downloading of an image will be faster after knowing the dimensions of the images in the browser.

Question 5. What do you mean by hypertext?
Answer: Hypertext acts as a link on which you click to navigate to the desired content.

Question 6. In HTML, how linking can be done?
Answer: In HTML, linking can be done by using anchor <a> tag followed by href attribute.

Question 7. Explain linking.
Answer: When one Web page or a text fragment is connected to another Web page, then it is called linking. It is of two types— internal linking and external linking.

Question 8. What happens when we click on a hyperlink in a Web page? CBSE 2008
Answer: When we click on a hyperlink in a Web page, it provides a link that leads from one document to another.

Question 9. Give the expansion of the following

alt
<a>

Answer:

alt is used for alternate text attribute.
<a> is used for anchor tag.

Question 10. Write the HTML command to display the following in your Web page. A² + B² CBSE 2006
Answer: The HTML command is – A2 + B2

Question 11. Write the output on the Web page for the following HTML command.
Atomic weight of O2
Answer: The output on the Web page will be Atomic weight of O₂

Short Answer Type Questions [2 & 3 Marks each]

Question 1. Describe the use of alt attribute with <img> tag.
Answer: The alt attribute is used to define ‘alternate text’ for an image. It tells the Website visitor, what he/she is missing on the page if the browser cannot load images. The browser will then display the altertnate text instead of the image. It is good to include alt attribute for each image on a page to improve the appearance and usefulness of the document.

Question 2. Write the HTML code to display an image on the right side of the page. CBSE 2016
Answer:

<html>
<body>
<img src="image.jpg" align="right">
</body>
</html>

Question 3. Name the values that can be assigned to align attribute of <img> tag.
Answer: The values that can be assigned to align attribute of <img> tag are as follows:

top
bottom
left
right
middle

Question 4. Write the HTML code to display an inline image named pencil.jpg located at C:\ in the center of your Web page. CBSE 2013
Answer:

<html>
<body>
<center>
<img src="C:\pencil.jpg">
</center>
</body>
</html>

Question 5. Define height and width attributes of <img> tag.
Answer: The width and height attributes tell the dimension of an image to the browser. Both (height and width) attributes require integer values (dimension of image in terms of either pixels or percentage of its actual size).
<img src=”picture.jpg” height = “50” width = “50”>

Question 6. Identify the errors in the following HTML code and write the correct code with each correction underlined. CBSE 2011

<html>
<title>IMAGES</head>
<body bgcolor="PICI.JPG">
<img href="ABC.JPG">
HERE IS MY IMAGE FILE
</bgcolor>
</html>

Answer:

Error 1 The <title> tag must be within <head> element.
Error 2 bgcolor attribute of body element supports a color like red, green or its color value.
Error 3 <img> tag needs a source attribute src to place an image.
Error 4 body element must be closed not bgcolor attribute.

The correct code is as follows:
<html>
<head>
<title>IMAGES</title>
</head>
<body bocolor = "yellow">
<imq src= "ABC.JPG">
HERE IS MY IMAGE FILE </body>
</html>

Question 7. Explain the need of linking between Web pages.
Answer: Linking between different Web pages is required, as when we create Websites, different html files (Web pages) are created. These files contain different modules and cannot be open individually. If we link between them, the Website becomes more productive and informative.

Question 8. How is external linking different from internal linking? CBSE 2004, 05
Answer: External link is a type of linking that goes to another Website. It is a linking of two different documents. While, internal linking is a type of linking that links pages within a single Website, various sections of same document or different document.

Question 9. Explain the given command
<a href =”wild.html”>Click Here for wild animals</a> CBSE 2006
Answer: In this command, anchor <a> tag and its href attribute is included. The text (Click Here for wild animals) will appear underlined and indicates that clicking the text activates the hypertext link. The address of the referenced document can be specified by an absolute or relative URL.
Thus, “wild.html” is an URL or Web page address and Click Here for wild animals is the hyperlinked text.

Question 10. Name the attributes of <a> tag which are used for internal linking in a Web page. CBSE 2014, 13
Answer:The attributes of <a> tag which are used for internal linking in a Web page as follows:

href used to specify the URL of the segment the link goes to.
name gives the name to the segment.

Question 11. What is the purpose of using the attribute href in <a> tag?
Answer: The href stands for Hypertext Reference. The href attribute is used with <a> tag to specify link to some other HTML page or Website.
e.g. <a href “”https://meritbatch.com”>
click here </a> to go to learncbse.
It will display like:
click here to go to learncbse.

Question 12. Write the HTML code to create a link for school .jpg located at C:\. CBSE 2014
Answer:

<html>
<body>
<a href = "C:\school. jpg">Image</a>
</body>
</html>

Question 13. Write an simple HTML code to show an example of internal linking.
Answer:

<html>
<head><title>Internal Linking</title>
</head>
<body>
<h1>It is <a name ="top">top</a> of the page </h1>
<br><br><br><br><br><br><br><br><br><br>
<br><br><br><br><br><br><br><br><br><br>
<br><br><br><br>
<h1><a href ="#top">Top</a></h1>
</body>
</html>

Question 14. What is the purpose of mailto function?
Answer: The mailto function is used to send E-mail messages to multiple recipients. For this, we only need to type the E-mail address of the recipients in the same link separated by commas.

Question 15. Write an HTML code to show the use of mailto function.
Answer:

<html>
<head>
<title> Use of mailto </title>
</head>
<body>Send your views to
<a href= "mailto:[email protected]"> [email protected]< / a >
</body>
</html>

Question 16. Write the HTML code to send an E-mail to [email protected] from your Web page. CBSE 2013
Answer:

<html>
<body>
<a href="mailto:[email protected]">[email protected]</a>
</body>
</html>

Question 17. Distinguish between and tags with example.
Answer: Distinguishes between and tags are as follows:

<sup> Tag	<sub> Tag
The <sup> tag is known as superscript tag.	The <sub> tag is known as subscript tag.
It is used to define superscripted text.	It is used to define subscripted text.
Tags that are used to specify superscripted written as <sup> text </sup>	Tags that are used to specify subscripted written as <sub> text </sub>
e.g. HTML command to display (a+ b) ² is (a+ b) <sup>2</sup>	e.g. HTML command to display log ₂+log _x is log <sub>2</sub>+log <sub>x</sub>

Question 18. Write the full forms of: CBSE 2013

<a>
<img>

Answer:

Superscript
<a> Anchor
<img> Image
Subscript

Long Answer Type Questions [5 Marks each]

Question 1. Explain various attributes of <img> tag.
Answer:

Attributes of <img> Tag
An attribute is an extra piece of information associated with a tag that provides further details about the tag.
Following are the various attributes of <img> tag:

The src Attribute: The src (source) attribute takes URL (Universal Resource Locator) of an image file as value, which points to the direct location of an image to be displayed.
The image that you specify in your <img> tag should be in your computer otherwise the image will not be displayed and in place of image a cross mark in a box 0 will appear.

The alt Attribute: This attribute of <img> tag is used to provide alternate text when an image on a Web page cannot be displayed.
The alternative text is the text associated with an image that serves the same purpose and conveys the same essential message. As per HTML standard, alt attribute is optional but is highly recommended.

The align Attribute: This attribute is used to set the position of an image in a Web page according to the user’s requirements. In HTML, images appear inline with a single line of the text. But, HTML standard does not define a default alignment for the images with respect to other text and images in the same line.
There are some values of image alignment attribute as follows:

Top Alignment
Middle Alignment
Bottom Alignment
Left Alignment
Right Alignment

The width and height Attributes: When an image is added to a Web page, it is not mandatory to specify width and height of the image. At the time of loading an image, a box will appear on the place where the image will be loaded.

The border Attribute: You can set the border of an image that you want to use in your Web page. The border attribute of the <img> tag specifies the width of the border around an image. By default, an image has no border in HTML.

Question 2. Which attribute is used to specify the location of an image file in <img> tag? Explain.
Answer: The attribute you need to get an image to display on a Web page is the src attribute.
In the src attribute of the <img> tag, you can specify the path of the image that you want to add to the Web page. This may be an image in the same directory, an image somewhere else on the same server, or an image stored on another server.
The syntax for src attribute is <img src =”imagel. jpg”>

Question 3. Define various alignments of align attribute with example.
Answer: There are some values of image alignment attribute as follows:

Middle Alignment
This alignment is different in both Internet Explorer and Mozilla Firefox. In Internet Explorer, this alignment aligns the image to the middle of the tallest item in the current line. While in Mozilla Firefox, this alignment aligns the image to the baseline of the current line in which it is placed.

Example: To show middle alignment of an image.
<html>
<head>
<title> Alignment </title>
</head>
<body>
<h1> Middle Alignment </ h1>
<img src="flower2.jpg" align="middle">
A flower, sometimes known as a b'oom or blossom, is the reproductive structure found in flowering plants. The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs.
</body>
</html>

Bottom Alignment
This alignment aligns the bottom edge of the image, to the same horizontal plane as the baseline of the text. Both Internet Explorer and Mozilla Firefox treat this alignment in the same manner.

Example: To show bottom alignment of an image.
<html>
<head> <title> Alignment </title> </head>
<body>
<h1> Bottom Alignment </h1>
<img src="flower2.jpg" alt="flower" align="bottom">
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants. The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs.
</body>
</html>

Left Alignment
This alignment aligns the image to the left on the Web page respectively of the browser window.

Example: To show left alignment of an image.
<html>
<head> <title> Alignment </title> </head>
 <body>
<h1> Left Alignment </h1>
<img src="flower2.jpg" align="left">
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants. The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs.
</body>
</html>

Right Alignment
This alignment aligns the image to the right on the Web page respectively of the browser window.

Example: To show right alignment of an image.
<html>
<head> <title> Right Alignment </title> </head>
<body>
<h1> Right Alignment </h1>
Cimg src="flower2.jpg" align="right">
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants. The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs.
</body> 
</html>

Question 4. Write HTML code to illustrate

listed hyperlinks
image hyperlinks

Answer:

Listed Hyperlinks: It is noticeable that <a> tag can also be used for more complex task (as with images or with lists etc.)

Example: To show listed hyperlinks.
<html>
<head> <title> List </title> </head>
<body> <h1>List </h1>
<ul>
<li> <a href="linkl.html"><img src ="F:Fruits-wallpaper-91.jpg" align="middle" height="75" width="75">
Fruit Chart </a></li><br><br>
<li> <a href= "link2.html">
<img src="F:\vegetable.jpg" align="middle" width="75" height="75">
Vegetable Chart </a> </li > </ul>
</body>
</html>

Output:

Image Hyperlinks: Images can also be used as hyperlinks. To create image as a link, following syntax is used:
<a href = “URL”> <img src=”image1.jpg”> </a>

Example: To show image as link.
 <html>
 <head>
 < title>Image as Link</title)
 </head>
 <body>
 <a href "http://en.wikipedia.org/wiki/Tweety")
 <img src="D:\Class10\computer\tweetyl.jpg"></a>
 </body>
 </html>

Output:

Question 5. Explain the following (with example):

linking on same Web page.
linking on different Web page.

Answer:

Linking on the Same Web Page

To create an internal link, you need to use a pair of <a> tags. The first <a> tag is used to specify the name of the target location for identification purpose. It is known as target fragment. You can use the <a> tag with its name or id attribute to identify a fragment. This type of anchor is commonly called as named anchor.
The first step is to make the target fragment. The simple syntax to do so is written below:
<a name =”aa”> Part A </a>
Where, “aa” is the name of fragment/segment you want to refer (like top, bottom etc.). The second <a> tag is used to create a link to the target fragment. The simple syntax to link to the target segment is written below:
<a href = “#aa”> ClickHere </a>
In the second <a> tag, the value of href attribute with # symbol is to be specified.

Example: To show the internal linking in an HTML document.
<html>
<head><title>Internal Linking<title></head>
<body>
<h1>Linking in a page </h1>
<h3>Click here to go to the
<a href="#bottom">bottom</a> of the page.</h3>
<br>><br><br><br><br><br><br><br><br> 
<br>><br><br><br><br><br><br><br><br>
<br>><br><br><br><br><br><br><br><br>
<a name="bottom"><h3> You are at the bottom of the page.</h3></a>
</body>
</html>

Output:

Linking Sections of Different Web Pages

Internal linking enables us to link sections of different Web pages also. It can be done by specifying the name of the Web page and the section which is to be linked. To link two Web pages, you first need name to the section by using name attribute of <a> tag that you want to link. Suppose, we need to link a section of HTML1.html to HTML2.html. Create a named anchor in HTML1.html.
The syntax is given below:
<a name =”link”> Different Page </a>
After this, you have to write the code to refer to it, from Web page HTML2.html. Following is the code to do so:
<a href =”HTML1.html#link”>
Here, HTMLl.html is the name of html file to the section of which you want to link and # link is the segment name you want to link in that html file.

Multiple Choice Questions [1 Mark each]

Q1. Web browsers display images in the following format
(a) XBM
(b) JPEG
(c) GIF
(d) All of these
Answer: (d) All of these

Q2. Which tag is used to insert an image in Web page?
(a) <a>
(b) <table>
(c) <img>
(d) 
Answer: (c) <img> tag is used to insert inline image in a Web page.

Q3. The correct HTML code for inserting an image is CBSE 2012
(a) <img href=”image.gif”>
(b) <img> image.gif</gif>
(c) <img src = “image.gif”>
(d) <image src = “image.gif” >
Answer: (c) <img src=”image.gif “>

Q4. src attribute used with <img> tag stands for CBSE 2013
(a) screen (b) screen resolution count
(c) source (d) structure
Answer: (c) source

Q5. …………. attribute is used to specify the location of an image file.
(a) alt
(b) src
(c) align
(d) name
Answer: (b) src attribute is used to specify the location of an image file.

Q6. The text specified in the alt attribute is displayed as tooltip in
(a) Internet Explorer
(b) Google Chrome
(c) Both (a) and (b)
(d) None of these
Answer: (a) The text specified in alt attribute is displayed as tooltip in Internet Explorer only.

Q7. The alternate text of an image can be displayed by using attribute of the <img> tag.
(a) src (b) alt
(c) align (d) None of these
Answer: (b) alt attribute of the <img> tag is used to display the alternate text of an image.

Q8. alt attribute allows CBSE 2016
(a) addition of an alternate hyperlink
(b) addition of a border to image
(c) use of an alternative image in place of the specified image
(d) addition of alternative text about an image
Answer: (d) alt attribute allows addition of alternative text about an image.

Q9. The default alignment of images, that are inserted in Web page, is
(a) left
(b) right
(c) inline with text
(d) middle
Answer: (c) An image which is inserted in Web page by default placed inline with text.

Q10. Which is not a valid value in the align attribute of <img> tag? CBSE 2014,2013
(a) top
(b) center
(c) bottom
(d) right
Answer: (b) center is not a valid value in the align attribute of <img> tag. To align in center, <center> tag can be used.

Q11. Why is it important to specify width and height attribute in <img> tag? CBSE 2013
(a) To ensure that image is not copied
(b) The image will not render without these
(c) To stop the image from loading
(d) Helps the browser to load the Web page faster
Answer: (d) Helps the browser to load the Web page faster.

Q12. When creating a Web document, which unit is used to express an image’s height and width? CBSE 2013
(a) Centimetres
(b) Pixels
(c) Dots per inch
(d) Inches
Answer: (b) Image’s height and width unit are expressed in pixels or in per cent form.

Q13. The <a> tag is
(a) a container tag
(b) an empty tag
(c) a closing tag
(d) None of these
Answer: (a) <a> is a container tag, which requires starting as well as matching ending tag.

Q14. ………… is the default color of a hyperlink.
(a) Red
(b) Blue
(c) Green
(d) Black
Answer: (b) Blue

Q15. The tag used in HTML to link a Web page with other Web page is CBSE 2013
(a) <a> (b) <h> (c) (d) <l>
Answer: (a) <a> anchor tag is used to create links.

Q16. Which tag tells, where a link starts? CBSE 2014
(a) <1> (b) <start>
(c) <a> (d) None of these
Answer: (c) <a> tag specify that a link starts, in which, href create a hyperlink.

Q17. Which command should be use to link a page with HTML page? CBSE 2013
(a) <a link = “page.htm” > </a>
(b) <a href = “page.htm”>page</a>
(c) <a connect = “page.htm”></a>
(d) <a attach = “page.htm”></a>
Answer: (b) <a href=”page.htm”>page</a>

Q18. With which code you .can make an image works as link? CBSE 2016
(a) <a href = “URL”>Text</a>
(b) “<a href=”ABC.html”><img src =”graphic.gif”>Click Here</a>
(c) <a ref=mailto:<img src = graphic.gif>Click Here</a>
(d) None of the above
Answer: (b) With <a href=”ABC.html”><img src= “graphic.gif >Click Here</a> image works as link.

Q19. To create a hyperlinked image
(a) the image tag should be within anchor tag
(b) the anchor tag should be within image tag
(c) the image tag should be before the anchor tag
(d) the image tag should be after the anchor tag
Answer: (a) The image tag should be within anchor tag to create hyperlinked image.

Q20. For internal linking, the section names are provided by attribute of <a> tag.
(a) title
(b) href
(c) name
(d) None of these
Answer: (c) For internal linking, section names are provided by name attribute.

Q21. Is it possible to link within the current page?
(a) No
(b) Only in framesets
(c) Yes
(d) None of these
Answer: (c) Yes, it is possible to link within the current page, which is called internal linking.

Q22. ………. attribute of the <a> tag is used to name a section in a Web page to create an internal link.
(a) href
(b) name
(c) align
(d) link
Answer: (b) name attribute is used to create an internal link.

Q23. …………….. attribute is used to set the color of a link while it is active.
(a) vlink
(b) alink
(c) Both
(a) and (b)
(d) None of these
Answer: (b) alink attribute is used to set the color of link while it is active.

Q24. The attribute which is used to send E-mails through a Website.
(a) tomail
(b) mailto
(c) Both
(a) and (b)
(d) None of these
Answer: (b) mailto attribute is used to send E-mails through a Website.

Q25. Choose the correct syntax to create an E-mail link. CBSE 2014
(a) <a href = “[email protected]”>
(b) <a href = “mailto:[email protected]”>
(c) email = “[email protected]”>
(d) <amail = “[email protected]”>
Answer: (b) <a href = “mailto:[email protected]”>

Q26. To display (X+Y)², correct HTML code is CBSE 2013
(a) (X+Y)2
(b) X+Y 2 
(c) (X+Y)2
(d) (X +Y)2
Answer: (c) (X+Y) 2 code is correct because superscript have to be placed in between and tags.

Fill in the Blanks [1 Mark each]

Q1. The <img> tag is an ………… tag, that means it has no closing tag.
Answer: empty

Q2. <img> tag is used for …………. images. CBSE 2014
Answer: displaying

Q3. …………… tag is used to create inline images. CBSE 2013, 2012
Answer: <img>

Q4. ……………. is an attribute of the <img> tag which specifies the location or URL of the image to be displayed.
Answer: src

Q5. An attribute is an extra piece of information associated with a …………….
Answer: tag

Q6. The ait attribute provides …………… for an image.
Answer: alternative information

Q7. The value for alt attribute is a text string of upto ………….. characters.
Answer: 1024

Q8. An image to be displayed in a Web page has to cover 25% of the browser window horizontally and 50% vertically. The attributes ………… and ………….of the <img> tag would be used for achieving this.
Answer: height, width

Q9. attribute is used to give border to an image. CBSE 2016
Answer: border

Q10. ………… is a word or image that when clicked take us to another Web page. CBSE 2013
Answer: Hyperlink

Q11. ………… tag is used to connect Web pages. CBSE 2014
Answer: <a>

Q12. ……. are used to connect Web pages. They are created with <a> tag. CBSE 2016
Answer: Hyperlinks

Q13. The …………. tag is considered to establish a hypertext relationship between the current document and another URL.
Answer: <a>

Q14. The ………….. attribute is used for specifying the URL of the anchor tag.
Answer: href

Q15. An ……….. link allows a link to another Web page or another Website. CBSE 2011
Answer: external

Q16. The …………….. attribute of <a> tag is used to provide information or a title for the linked document or Web page.
Answer: title

Q17. An link allows a link to another section on the same or different Web page.
Answer: internal

Q18. A visited link on a Website is generally underlined and …………… in color.
Ans. purple

Q19. The default color of alink attribute is ………… .
Answer: red

Q20. ………… is used to change the color of a visited link. CBSE 2016
Ans. vlink

Q21. Using the ………… type URL, you can create the E-mail hyperlink.
Answer: mailto

Q22. The tag ……….. is used to create superscripts and …………. tag is used to create subscripts on a Web page.
Answer: ,

True or False [1 Mark each]

Q1. You can have inserted an image in your Web page which is physically present in your computer.
Answer: True With the help of <img src=”image URL”>, we can insert an image in Web page which is present in our computer.

Q2. If the image you are loading in the Web page is not available, then you want a text to appear in the image placeholder, text attribute lets you define this text.
Answer: False The alt attribute is used to define text to appear in the image placeholder, if image is not visible for any reason.

Q3. No value is specified with alt attribute of <img> tag. CBSE 2012
Answer: False alt attribute provides alternate text for an image if the image is not visible on Web page for any reason.

Q4. String as a value of alt attribute must be enclosed in quotation marks.
Answer: True alt attribute contains string which must be enclosed in quotation marks.

Q5. The general syntax for inline image is <img src = “file name” >.
Answer: True At the place of file name, path of the image is specified. If the image is in the same folder as HTML file, it is not needed to specify full path of an image.

Q6. The default alignment of image is right. CBSE 2014
Answer: False There is no default alignment of image with respect to text in HTML.

Q7. It is not important to specify an integer value as the width of the border of an image.
Answer: False Width takes an integer values that are in pixels.

Q8. The align attribute of the <img> tag is used to specify the text that is to be displayed in case the browser that does not support graphics.
Answer: False alt attribute is used to specify the text that is to be displayed in case the browser which does not support graphics.

Q9. We can put a border around an image by using width attribute. CBSE 2013
Answer: False We can put a border around an image by using border attribute.

Q10. border is an attribute of <a> tag. CBSE 2012
Answer: False border is an attribute of <img> tag.

Q11. The <a> tag is called the align tag. CBSE 2011
Answer: False The <a> tag is called anchor tag.

Q12. The anchor tag <a> signals the beginning of the text.
Answer: False Anchor tag is used to create hyperlinks not text.

Q13. The color of the hyperlinks in an HTML document can be changed.
Answer: True We can change the color of hyperlinks in HTML document.

Q14. Hyperlinks can also be created for links within the same document. Linking within the same document is called external linking.
Answer: False Linking within the same document is called internal linking.

Q15. It is not possible to create link within current document. CBSE 2012
Answer: False You can link various sections of the current document together, which is called internal linking.

Q16. The name attribute of the <a> tag allows the user to create links within the same document. CBSE 2011
Answer: True Because name attribute defines a name of a section in a document.

Q17. You should include a mailto function in the body of your document to allow user to respond to your Web page.
Answer: True The mailto function is used to send E-mails from the Website.

NCERT Solutions for Class 10 Foundation of Information Technology – Societal Impacts of IT

May 20, 2022

NCERT Solutions for Class 10 Foundation of Information Technology – Societal Impacts of IT

Very Short Answer Type Questions [1 Mark each]

Question 1. Define virus.
Answer: A virus is a harmful program, which on entering a computer, starts creating copies of itself. It then attacks by corrupting the executable files and folders saved on the computer.

Question 2. List the different types of computer viruses.
Answer:

File system viruses
Boot sector viruses
Macro viruses

More Resources for CBSE Class 10

Question 3. Name some forms of virus attacks.
Answer: Worms, Trojan horse, Computer Virus etc.

Question 4. Give some examples of computer worms.
Answer: MS-Blaster, Mellisa worm, SQL Slammer worm are the common examples of worms.

Question 5. Explain denial of service attack.
Answer: A denial of service attack is a type of attack that consumes all the resources of a computer.

Question 6. What is used to identify, prevent and take action against malicious programs, such as viruses and worms, by deactivating or deleting them?
Answer: Antivirus is used to identify, prevent and take action against malicious programs such as viruses and worms, by deactivating or deleting them.

Question 7. Describe hacking.
Answer: Hacking is the practice of modifying the features of a system, in order to accomplish a goal outside of the creator’s original purpose.

Question 8. What is the meaning of backup? CBSE 2013
Answer: Backup is a process of making an extra copy of the data on a computer and storing it in a different location on the computer or in an external device.

Question 9. What are the types of data backup?
Answer: There are two types of data backup:

Full backup
Differential backup

Question 10. Can you backup the files while your computer is running?
Answer: Yes, we can safely backup open files and programs while they are running.

Question 11. What is encryption of data? CBSE 2014
Answer: Encryption refers to scrambling of data in some encoded format so that it may be transmitted over networks.

Question 12. A digital signature is issued by which organisation?
Answer: A digital signature is«an electronic file that is issued by a Certification Authority. (CA).

Question 13. Name two other means of online security measures.
Answer: Digital signature and Digital certificate

Question 14. Which security provision is used to ensure data integrity and authentication?
Answer: A digital signature helps the user to ensure data integrity and authentication.

Question 15. Give any two shortcomings of online purchase. CBSE 2014
Answer:

Cannot see the product in reality before a purchase.
You do not receive the product immediately, there is always some delay.

Short Answer Type Questions [2 & 3 Marks each]

Question 1. How does a virus affect your computer?
Answer: Virus is a software used to infect a computer. After virus code is written, it is buried within an essential programmed. Once the programmed is executed, the virus code is activated and attack copies itself to other programs.

Question 2. Give three guidelines to prevent the virus attack.
Answer: Three guidelines to prevent the virus attack are as follows:

Avoid the temptation to open unexpected E-mail attachments and downloads from unreliable sources. Resist the urge to double click everything in your mailbox. If you get an unexpected file attachment, send an enquiry E-mail to its sender. Ask him about the nature and function of the file attachment.
In stable reliable antivirus, scanning software and download its updates regularly.
Scan files downloaded from the Internet or other external sources.

Question 3. If your computer attacked by a trojan horse virus, what damage it may cause?
Answer: If your computer attacked by a trojan horse virus, it can:

Steal passwords
Copy sensitive data
Carry out any other harmful operations etc.

Question 4. Write minimum three ways by which a virus can spread to other systems.
Answer: Three ways by which a virus can spread to other systems are as follows:

When an infected file is copied through network.
When virus file is downloaded from Internet.
When infected file is copied from floppy disk, USB, DVD etc.

Question 5. Write any two tips to avoid spams. CBSE 2016
Answer: You can use the following guidelines to avoid spam, they are as follows:

Keep your E-mail address private.
Using appropriate filters to find and alter you about spam.

Question 6. What are the primary interest of online attackers in spyware?
Answer: Primary interest of online attackers in spyware is using it to steal personal information for financial crimes such as carding and identity theft or to sell that information to someone else who then executes more traditional financial crimes.

Question 7. What does an antivirus software do? CBSE 2014
or
What does an antivirus software do? Explain in brief with any two points. CBSE 2013
Answer:

Antivirus software is a computer program that detects, prevents and takes action to disarm or remove malicious software programs, such as viruses and worms.
Displays health of your computer system.

Question 8. What precaution you should take before copying file from an external storage media?
Answer: Precaution should be taken to run an antivirus program before copying any file from floppy disk, USB, DVD etc. Also, we have to run antivirus program weekly to scan all the drives in the system.

Question 9. List some commonly available antivirus programs.
Answer: Some of the commonly available antivirus programs in the market are as follows:

Symantec Norton antivirus
AVG antivirus
McAfee scan
Quick Heal

Question 10. Define information security.
Answer: Information security is all about protecting and preserving information. It’s all about protecting and preserving the confidentiality, integrity, authenticity, availability and reliability of information.

Question 11. Differentiate between full backup and differential backup.
Answer: Differences between full backup and differential backup are as follows:

Full backup	Differential backup
A complete backup of everything that you want to backup.	The backup software looks at which files have changed, since you last did a full backup.
Restoration is fast, since you only need one set of backup data.	Faster to create than a full backup.

Question 12. Write differences between online backup and offline backup. CBSE 2014
Answer: Differences between online backup and offline backup are as follows:

Online backup	Offline backup
You don’t have direct control over your data.	The data is totally in your control.
If you have a fire, flood, or theft, your backup is offsite so you don’t have to worry about it.	If you have a fire or flood, your backup might be damaged alongwith your computer.

Question 13. List two advantages of online backup. CBSE 2012, 2013
Answer: Two advantages of online backup are as follows:

By having your data stored on a remote hard drive, you run little as there is no risk of losing your data as a result of fire, theft or any other disaster.
No hardware is needed to maintain or repair the backup.

Question 14. Can firewalls detect virus?
Answer: Firewalls do not screen computer viruses.
As the location of firewalls is a good place for scanning, some firewalls has plug-in virus scanning module.
And some programs scan virus at a point either before or after a firewall.

Question 15. Mention three societal impacts of IT.
Answer: The societal impacts of IT are as follows:

Opportunities for people with disabilities through artificial intelligence.
Quality of life improvements due to E-Commerce over Internet.
Crime fighting and other benefits.

Question 16. Why should we frequently take backup of our data?
Answer: We frequently take backup of our data because

The hard drive of our computer may fail.
The data on our computer may get corrupted for a variety of reasons.
Data loss due to fire, natural disasters etc.

Question 17. Differentiate between digital certificate and digital signature. CBSE 2013
Answer: Differentiate between digital certificate and digital signature are as follows:

Digital certificate	Digital signature
Digital certificates are typically used in Websites to increase their trustworthiness to its users.	A digital signature is a mechanism that is used to verify that a particular digital document or a message is authentic.
Digital certificates are used, the assurance is mainly dependent on the assurance provided by the CA.	With digital signatures, the receiver can verify that the information is not modified.

Question 18. Name one specific software/tool for each of the following categories: CBSE 2011

Antivirus software
Data recovery tool
Online backup tool

Answer:

Antivirus software – Quick Heal
Data recovery tool – NTFS Reader
Online backup tool – Dropbox

Question 19. Give the three terms related to the following:

Attacks
Backup
Security software

Answer:

Attacks Trojan horse, Worm, Denial of Service.
Backup Online backup, Full backup, Differential backup.
Security software Digital signature, Firewall, Antivirus.

Question 20. Name four data backup devices/medium. CBSE 2016
Answer: Four storage media on which data backup may be taken are as follows:

DVD (Digital Versatile Disk)
External hard disk
USB flash drive
Memory stick

Long Answer Type Questions [5 Marks each]

Question 1. What are the common symptoms of a virus attack?
Answer: Symptoms of Computer Viruses Attack
The list of symptoms of computer viruses attack, which indicate that your system is infected with a computer viruses are as follows:

Odd messages are displaying on the screen.
Some files are missing.
System runs slower.
PC (Personal Computer) crash or restart again and again.
Drives are not accessible.
Antivirus software will not run or installed.
Unexpected sound or music plays.
The mouse pointer changes its graphic.
Receive strange E-mails containing odd attachments or viruses.
PC starts performing functions like opening or closing windows, running programs on its own.

Question 2. What are the various measures that should be taken to prevent spyware from overtaking your system?
Answer: Preventions of Spyware
Due to the seriousness of spyware and the harm, it can affect your system and personal information, it is highly recommended you to take the given measures to prevent spyware from overtaking your system:

Download and install anti-spyware software: Most antivirus applications are effective in identifying different types of malware, including spyware, but may not detect all spyware variants. Once you install the anti-spyware software on your computer, you must keep your anti-spyware application updated to keep up with the latest forms of spyware.
Be cautious when Web surfing: The best defense against spyware is not to download it in the first place. Spyware is often installed on your computer when you visit an infected or malicious Website.

Therefore, you should exercise caution with links to Websites from unknown sources. In addition, you should only download programs from trustful Websites. When downloading a specific program, ensure that you are not downloading pirated software. Spyware can be distributed by exploits, that promote software piracy.

Lookout for pop-ups: Malware can lure you into installing spyware on your computer by prompting you with a pop-up window. If you see an unwanted or random pop-up alert, do not click “Agree” or “OK” button to close the pop-up window. This will actually install the malware on your computer. Instead, press Alt + F4 or click on the red “X” on the corner on the pop-up alert to close the window.
Keep current with operating system updates: Important system updates provide significant benefits such as improved security. Just as with any antivirus and anti-spyware software, not keeping up with operating system updates will make your PC vulnerable to the latest malware threats.
Harden your browser settings: Updated Web browsers may help to prevent exploitation by taking several defensive steps against spyware. Most Web browsers will warn you of executable programs and will suggest a safe course of action. In addition to having an updated Web browser, ensure that you have properly configured your browser and that all of your plug-ins and add-ons are updated, including Java, Flash and Adobe products.
Enable your firewall: Firewalls monitor the network and are capable of blocking suspicious traffic, which can prevent spyware from infecting your system.

Question 3. Differentiate between hackers and crackers.
Answer: Differences between hackers and crackers are as follows:

Hackers	Crackers
A hacker is a person intensely interested in the arcane and recondite working of any computer operating system.	A cracker is one who breaks into or otherwise violates the system integrity of remote machines with malicious intent.
Hackers obtain advanced knowledge of operating systems and programming languages.	Having gained unauthorised access, crackers destroy vital data, deny legitimate users service, or cause problems for their targets.
Hackers constantly seek further knowledge, freely share what they have discovered and never intentionally damage data.	Crackers can easily be identified because their actions are malicious.

Question 4. Explain SET, PCI and Kerberos.
Answer:

PCI (Peripheral Component Interconnect) is a computer bus for attaching hardware devices in a computer. These devices can take either the form of an integrated circuit fitted onto the motherboard itself, called a planer device in the PCI specification or an expansion card that fits into a slot.
SET (Secure Electronic Transaction) protocol, which is developed by Visa and Mastercard uses encryption for privacy and digital certificates to verify the three parties -the bank, the customer and the merchant. It ensures secure transactions online.
Kerberos is a third-party authentication that validates the clients over the network and provides secure communication or access to network resources.

Question 5. Write a short note on social networking.
Answer: It is a grouping of individuals into specific groups, like small rural communities or a neighbourhood subdivision, if you will. A social networking service is an online service, platform or site that focuses on facilitating the building of social networks or social relations among people.
e.g. people who share interests, activities, backgrounds or real life connections. When it comes to online social networking, Websites are commonly used. These Websites are known as Social Sites. The most popular social sites are currently Facebook, MySpace, Orkut etc.
These Websites provide users with simple tool to create a custom profile with text and pictures. Typical profile includes basic information about user, atleast one photo and possibly a blog or other comments published by the user. It may include videos, photos albums, online applications as in Facebook or custom layout (in MySpace). After creating a profile, user can send message to other users and leave comments directly on friends’ profiles.

Question 6. Write the benefits of ICT in education and healthcare.
Answer: Benefits of ICT
ICT has become an integral part of our daily life. And, it has benefited the common man in various ways in every field of life. Some of them are as follows:

In Education
The main purpose of the strategy for ICT implementation in education is to provide the prospects and trends of integrating ICT into the general educational activities.

Some benefits of ICT in education are as follows:

There is no time boundation on an individual for getting educated by a teacher. A person can attend a class anytime and anywhere.
Teachers can create interactive classes and make the lessons more interesting.
Generally, students find images and graphical representation of concepts, more interesting as compared, to the theoretical knowledge. And, using ICT, teachers can explain even the most complex concept in a very simplified manner using graphics, videos and animations.
An individual can learn on pace he/she is comfortable.
Learning resoures can be accessed remotely.

In Healthcare
Some benefits of ICT in healthcare are as follows:

Automated hospital information systems can help to improve quality of care.
Decreased costs of treatment.
ICT has significantly enhanced the services being provided and brought behavioural changes.
This technology helps doctors, hospitals, the general public and all other medical care providers.
Pharmaceutical industry is the industry that enjoys the biggest benefits of ICT.
ICT has made E-Health possible.

Question 7. “Virtual schools are better than traditional schools.” Write reasons to support this statement.
Answer: A virtual school is a learning environment offered entirely on the Internet. All student services and courses are conducted through Internet technology. The virtual school differs from the traditional school through the physical medium that links administrators, teachers and students. It refers to an institution that is not “brick and mortar” bound.

Advantages
The advantages of virtual schools are as follows:

Individualised instruction for all students.
Lessons can be taught in a way that benefits students with various learning abilities.
More time can be spent on lessons that are more difficult for students.
Flexibility for the students to learn whenever and wherever they want.
Students are self-directed and mature quicker as they manage their studies.
Students can access learning 24 hours a day and learn at their own pace.

Disadvantages
The disadvantages of virtual schools are as follows:

Undisciplined students will not succeed in the online environment.
Puts more stress on the parents to provide guidance and tutoring.
Parents need to monitor the student all day long as opposed to dropping the student at school where the student is monitored by teachers and staff.
Students are more isolated and might not developed properly socially.
Students would not receive personal one-on-one time with teachers.

Question 8. Give one word answer CBSE 2012

Another name for junk mails.
It is doing business online.
It is the crime committed using computers and Internet.
The programmer that breaks into secure systems with non-malicious intentions.
Type of malware that is installed on user’s computer and collects information about user without his consent.

Answer:

Spam
E-Business/E-Commerce
Cyber crime
Hacker
Spyware

Application Oriented Questions

Question 1. Amit installed an antivirus software to remove all the viruses from his computer.

What is antivirus software?
Name two actions performed by an antivirus software.

Answer:

Antivirus software is used to identify, prevent and take action against malicious programs, such as viruses and worms, by deactivating or deleting them.
Two actions performed by an antivirus software are as follows:
(a) Scanning E-mail messages and their attachments.
(b) Scanning and monitoring files and folders on your computer to ensure that they are not infected.

Question 2. It is an electronic messaging system used by various commercial organisations to send bulk messages to a large number of E-mail addresses. What is it?

E-mail
Spam
SMS
Adware

Answer: 2. Spam

Question 3. Shreenivasan is working for an IT firm where he needs to backup of his data of around 200 MB to 400 MB at the end of each day. Each day backup needs to archived separately for future reference. Suggest any two economic data backup devices, which he can use for this purpose.
Answer: DVD and Pen drive

Question 4. Mohan has downloaded few attachments in his mail to his system from Internet. When he opened those attachments there were multiple copies of the same file opened. After sometime his system got rebooted automatically. He is unable to find out why his system is not responding properly. Can you tell what happened to his system and give him some solutions? CBSE 2016
Answer: There is a virus (most likely worm) in Mohan’s computer, that has caused damage to data and files on his system. He should install antivirus software, such as Kaspersky, Quick Heal, McAfee etc., as the main defence against online problems. He should take backup of his files regularly.

Question 5. In a small office network, to protect every computer from hackers, virus or worm. Which statement do you think is True or False from the given options?

Set Firewall Turned ON
Install antivirus software.
Allow users to use external disk drives.
Download attachments from reliable source even without scanning. CBSE 2016

Answer:

True
True
False
False

Multiple Choice Questions [1 Mark each]

Q1. …………… stands for Malicious Software, is software designed to infiltrate a computer system without the owner’s informed consent. CBSE2011
(a) Blog
(b) Attachments
(c) Spam
(d) Malware
Answer: (d) Malware designed to interrupt ongoing computer operations, collect private information and gain unauthorised access to your system resources.

Q2. Which one of the following is not a malware? CBSE 2016
(a) Computer virus
(b) Spam
(c) Worm
(d) Application software
Answer: (d) Application software refers to the condition in which your computer stops working.
(a) Hang
(b) Virus attack
(c) Hacking
(d) None of these
Answer: (a) Hang refers to the condition in which your computer or a software stops working.

Q3. Which of the following is not a symptom of a virus attack?
(a) The computer begins to run slowly
(b) Unusual messages and graphics appear on the screen for inexplicable reasons
(c) Some programs or data files on the computer either become corrupt or are difficult to locate
(d) Your data is copied to another location
Answer: (d) Your data is copied to another location is not a symptom of a virus attack.

Q4. A good way to safeguard access to your computer is to protect it.
(a) Deadbolt
(b) Copyright
(c) Safemode
(d) Password
Answer: (d) Password is a good way to safeguard access to your computer to protect it.

Q5. Which of the following is the first computer virus?
(a) Brain
(b) Melissa
(c) Elk Cloner
(d) I Love You
Answer: (c) Elk Cloner is the first computer virus created by Richard Skrenta.

Q7. Out of the following, which one will be altered or modified by a computer virus? CBSE 2011
(a) Operating system
(b) Speed of network connectivity
(c) Application software
(d) All of the above
Answer: (d) All of the above

Q8. Which one of the following is not a way to get a computer virus? CBSE 2016
(a) Through E-mail attachments
(b) Through pen drive
(c) By typing on keyboard
(d) By downloading files
Answer: (c) By typing on keyboard is not a way to get a computer virus.

Q9. The at first glance will appear to be useful software but will actually do damage once installed or run on your computer.
(a) worm
(b) virus
(c) trojan
(d) spam
Answer: (c) The trojans are unauthorised programs placed inside a legitimate application.

Q10. A …….. is a virus that is often disguised as a useful computer program. CBSE 2012
(a) trojan horse
(b) hacker
(c) worm
(d) spam
Answer: (a) Trojan horse is a virus, i.e. often disguised as a useful computer program.

Q11. A ……. is a software program that is designed to copy itself from one computer to another, without human intervention. CBSE 2011
(a) trojan
(b) vims
(c) worm
(d) spam
Answer: (c) A worm is a self-replicating software program. It does not require another program to host it.

Q12. Which of the following is not an example of worm?
(a) MS-Blaster
(b) Sobig
(c) De bumper
(d) Melissa
Answer: (c) De bumper is a type of trojan horse.

Q13. Which of the following statements is incorrect in the context of a worm?
(a) It represents a category of malware
(b) It creates infections in a computer
(c) It is self replicating
(d) It cannot travel on its own
Answer: (d) Worm is self replicating software and thus, it can travel on its own.

Q14. A category of software that spies of your computer activities is
(a) De-ware
(b) Spyware
(c) Utilities
(d) Freeware
Answer: (b) Spyware is a category of software that spies computer activities.

Q15. The electronic equivalent of junk mail is known as CBSE 2014
(a) adware
(b) cyber fraud
(c) spam
(d) packets
Answer: (c) Spam is an electronic equivalent of junk mail.

Q16. Which of the following is not antivirus software?
(a) Norton Antivirus
(b) Melissa
(c) McAfee
(d) SmartCop
Answer: (b) Melissa is a macro virus, not an antivirus.

Q17. To avoid problems while working on the Internet, you should follow these precautions.
(a) Install antivirus on your computer
(b) Take the backup of your files regularly
(c) Do not click on unknown links
(d) All of the above
Answer: (d) All of the above

Q18. One limitation of antivirus programs is that they: CBSE 2016
(a) Sometimes start behaving like virus
(b) Are very expensive
(c) Harm the computer
(d) Can detect only those viruses for which they are programmed
Answer: (d) Antivirus can detect only those viruses for which they are programmed.

Q19. The programmers who break into secure systems for malicious purpose are CBSE 2014
(a) crackers
(b) hackers
(c) breakers
(d) burglars
Answer: (a) Crackers are the programmers that break into secure systems for malicious purpose.

Q20. A is someone who breaks into someone else’s computer system, often on a network; bypasses passwords or licenses in computer programs without malicious intent with a wish to learn and improve security.
(a) hacker
(b) cracker
(c) worm
(d) malware
Answer: (a) A hacker is a person who enjoys learning programming languages and about computer systems and their working.

Q21. A digital document issued to a Website by a certification authority on the Internet is called
(a) digital signature
(b) encryption
(c) digital certificate
(d) firewall
Answer: (c) A digital certificate is an electronic file that is issued by a certification authority to Websites.

Q22. You can transmit sensitive information, such as that relating to your credit card, by using
(a) PCI
(b) SET
(c) SSL
(d) Firewall
Answer: (c) SSL allows sensitive information such as credit card numbers to be transmitted securely.

23. Firewall:
(a) Amplifies weak outgoing signals to stronger ones
(b) Is the name of an open source browser
(c) Is the name of computer virus
(d) Prevents intruders from accessing your system
Answer: (d) A firewall can either be software based or hardware based and is used to prevent intruders from accessing your system.

Fill in the Blanks [1 Mark each]

Q1. ………… is the general term to refer to infectious software such as virus, worm, spyware etc.
Answer: Malware

Q2. A malicious program that is used to remove all information from your computer is known as ………
Answer: sweeper

Q3. A ……….. infects the files of the operating system.
Answer: boot sector virus

Q4. ……. and ………. are the two types of malware. CBSE 2011
Answer: Viruses, Worms

Q5. ……….. can decrease the space on hard disks by duplicating files.
Answer: Viruses

Q6. ……… is a program that appears harmless but actually performs malicious functions. CBSE 2014
Answer: Trojan horse

Q7. ……….. is a software program that is designed to copy itself from one computer to another. CBSE 2016
Answer: Worm

Q8. Unlike a computer virus, a ……….. can replicate itself automatically. CBSE 2011
Answer: worm

Q9. …………. is a type of malware that is installed on a user’s computer and collects information about user without their consent and knowledge. CBSE 2013
Answer: Spyware

Q10. Any crime committed using computers and Internet is termed as ………… CBSE 2013
Answer: cyber crime

Q11. ………. attack eats up all the resources of a system and halts it.
Answer: Denial of service

Q12. ……… is a computer program that detects, prevents and takes action to remove malicious software programs. CBSE 2016
Answer: Antivirus

Q13. Copy of data created for safe storage is …………
Answer: backup

Q14. ………… backup saves your data from natural disasters. CBSE 2012
Answer: Online

Q15. ……. is a type of backup in which only the data that changed, since last backup is saved.
Answer: Differential backup

Q16. A digital code attached to an electronic message to provide it unique identity is called ………… CBSE 2014
Answer: digital signature

Q17. ………. security technology establishes an encrypted link between a Web server and browser.
Answer: SSL

Q18. …… refers to the disparity of classification of person according to their knowledge of ICT and without it.
Answer: Digital divide

True or False [1 Mark each]

Q1. A virus may corrupt or delete data on your computer. CBSE 2011
Answer: True A virus may corrupt or delete data on your computer.

Q2. A virus is a harmful program, which one entering a computer, starts creating copies of itself.
Answer: True Virus is a malicious program that is designed to make a system sick, just like a real virus.

Q3. A worm is a self-replicating program which eats up the entire disk space. CBSE 2012
Answer: False Virus eats up the entire disk space.

Q4. Spyware is a type of malware but is not capable of collecting personal information. CBSE 2011
Answer: False Spyware is a type of malware used to collect personal information without his or her knowledge.

Q5. Adware is a ‘Software that posts unwanted advertisements on your computer.
Answer: True Adware is a software that is given to the user with unwanted advertisements embedded in the application.

Q6. Always scan the storage media before connecting it to your computer.
Answer: True You should always scan your storage media before connecting it to your computer.

Q7. SmartCop is an antivirus developed in India.
Answer: True SmartCop antivirus is developed in India.

Q8. Junk E-mails are also called spam. CBSE 2016
Answer: True E-mail spam, junk mail or junk newsgroup posting is a widely recognised form of spam.

Q9. Cracker is a person who breaks security to see what we have stored on our computers with mat intentions. CBSE 2016
Answer: True Cracker breaks security with mal intentions.

Q10. It is not necessary to regularly take back-up of important files. CBSE 2011
Answer: False A backup ensures that your computer data is protected or can be recovered.

Q11. CD is a storage device that is used to take the backup of your data.
Answer: True You can use different types of storage devices like CD, DVD to take the backup of your data.

Q12. You cannot keep the backup of your data online.
Answer: False In online backup, you send the data to a remote server through the Internet.

Q13. Backup is duplication of data for restoring purpose at a later time. CBSE 2014
Answer: True Backup is a process to copy the data and restore it, whenever required.

Q14. SET is a protocol developed by Visa and Mastercard.
Answer: True SET is a protocol developed by Visa and Mastercard. It ensures secure transactions over the Internet.

Category: Class 10

Class 10 Maths NCERT Solutions Chapter 1 Real Numbers

Real Numbers Class 10 Ex 1.1

Real Numbers Class 10 Ex 1.2

Real Numbers Class 10 Ex 1.3

Real Numbers Class 10 Ex 1.4

Class 10 Real Numbers Summary

Class 10 Maths Real numbers Mind Map

Euclid’s Division Lemma

Euclid’s Division Algorithm

Fundamental Theorem of Arithmetic

HCF and LCM of Three Numbers <img loading="lazy" src="https://i0.wp.com/live.staticflickr.com/65535/48287242967_32951ce31e_o.png?resize=492%2C136&#038;ssl=1" alt="NCERT Solutions For Class 10 Maths Chapter 1 Real Numbers 2" width="492" height="136" data-recalc-dims="1" />

Irrational Numbers

Rational Numbers and Their Decimal Expansion

NCERT Solutions for Class 10 Maths

S Chand Biology Class 10 Solutions Multiple Choice Questions (MCQs)

S Chand Biology Class 10 Solutions Model Test Paper 2

S Chand Biology Class 10 Solutions Model Test Paper 3

S Chand Biology Class 10 Solutions Model Test Paper 4

NCERT Solutions For Class 10 Maths Chapter 8 Introduction to Trigonometry Ex 8.2

NCERT Solutions for Class 10 Maths Chapter 8 Introduction to Trigonometry (Hindi Medium) Ex 8.2

NCERT Solutions for Class 10 Maths

NCERT Solutions for Class 10 Social Economics Chapter 2 Sectors of Indian Economy

NCERT Solutions for Class 10 Social Economics Chapter 4 Globalisation and the Indian Economy

NCERT Solutions for Class 10 Social Economics Chapter 5 Consumer Rights

NCERT Solutions for Class 10 Foundation of Information Technology – Inserting Images and Links in HTML

NCERT Solutions for Class 10 Foundation of Information Technology – Societal Impacts of IT

HCF and LCM of Three Numbers