Students must start practicing the questions from CBSE Sample Papers for Class 11 Computer Science with Solutions Set 5 are designed as per the revised syllabus.
CBSE Sample Papers for Class 11 Computer Science Set 5 with Solutions
Time Allowed: 3 hours
Maximum Marks: 70
General Instructions:
- All questions are compulsory.
- Attempt all parts of each question
- Internal choices are given, choose any one of them.
Question 1.
(a) The set of instructions given to a computer is called ………………….. [1]
(A) Program
(B) ALU
(C) CU
(D) Storage
Answer:
(A) Program
(b) The None literal is used to indicate absence of a value. (True/false) [1]
Answer:
True
(c) Which are correct arithmetical operations? [1]
(A) a = 1*2
(B) 2 = 1 + 1
(C) 5 + 6 = y
(D) Seven = 3*4
Answer:
(A) a = 1*2
(D) Seven = 3*4
Explanation:
Arithmetic operators are used to perform mathematical operations like addition, Substraction, Multiplication, division, correct way of operation is Variable name = oprand with operators, eg. a = 1 * 2 Seven = 3*4
(d) Which are correct type conversions? [1]
(A) int (7.0+0.1)
(B) str (1.2 * 3.4)
(C) float (“77″+”.0″)
(D) str (9/0)
Answer:
(A) int (7.0+0.1)
(B) str (1.2 * 3.4)
(C) float (“77″+”.0″)
Explanation:
Python define type conversion function like int(), float(), Str (), to directly convert one data type into another option (D) is incorrect because division is perform by str type conversion i.e., string not supported.
(e) When an exception occurs, it is said that exception was ……………………. .[1]
(A) raised
(B) caught
(C) handled
(D) unhandled
Answer:
(A) raised
(f) What will be the output of following statements when inputs are a = 30, b = 20, c = 30? [2]
(A) print(a<b)
(B) print(b<=c)
(C) print(a<b<=c)
(D) None of these
Answer:
(A) False
(B) True
(C) False
Commonly Made Error:
It must always be remembered that the answer should be given by comparing the given a, b and c value.
Answering Tip:
Students must make accurate comparisons.
(g) Define the two types of spams. [2]
Answer:
The two types of spam are:
(i) Malicious: These are the mails that an attacker keeps on sending until the mail server runs out of space.
(ii) Non malicious spams: These are sent in bulk to recipients just for advertisements.
(h) Read the following text and answer the following questions on the basis of the same:
The technique to represent and work with numbers is called number system. Decimal number system is the most common number system. Other popular number systems include binary number system, octal number system, hexadecimal number system, etc. Decimal number system is a base 10 number system having 10 digits from 0 to 9. The number system having just these two digits – 0 and 1 – is called binary number system. Octal number system has eight digits – 0,1,2,3,4,5,6 and 7. Hexadecimal number system has 16 symbols – 0 to 9 and A to F where A is equal to 10, B is equal to 11 and so on till F. [4]
1. The value of radix in binary number system is _____________
(A) 2
(B) 8
(C) 10
(D) 1
Answer:
(A) 2
Explanation:
In a binary number system, the value of base or radix is 2. The binary system uses only two digits for the representation of numbers, therefore its base id has chosen to be 2.
2. Which two form the binary number system?
(A) 0 and 2
(B) 1 and 2
(C) 0 and 1
(D) 1 and 3
Answer:
(C) 0 and 1
Explanation:
The number system having just these two digits – 0 and 1 – is called binary number system.
Each binary digit is also called a bit. Binary number system is also positional value system, where each digit has a value expressed in powers of 2.
3. Which of the following is not an example of octal number?
(A) 123
(B) 478
(C) 372
(D) 136
Answer:
(B) 478
Explanation:
Octal number system has eight digits – 0,1, 2, 3,4,5, 6 and 7. Octal number system is also a positional value system with where each digit has its value expressed in powers of 8.
4. In hexadecimal system, each alphanumeric digit is represented as a group of ______________ binary digits
(A) 1
(B) 2
(C) 3
(D) 4
Answer:
(D) 4
Question 2.
(a) The smallest individual unit in a program is called …………………………… [1]
Answer:
Token
(b) When an application suddenly stops for no reason, it is because of an …………………………… [1]
Answer:
Error
(c) Write the statement to add a single item 25 to an existing tuple, Flowers. [2]
Answer:
Flowers = Flowers + (25,)
(d) Sarita learnt about some sequence in Python that stores data as key:value pairs, but she has forgotten its name, name it. is it mutable or immutable. [1]
Answer:
The sequence is dictionary and it is mutable
(e) Write a program to display sum of all even numbers upto a given number entered by the user. [4]
Answer:
e = 0
i = int (input ("Enter the maximum value of range") )
for j in range (i + 1):
if j%2 == 0:
e += j
print (e)
Question 3.
(a) kishore is sales manager of xyz corp. He wants to calculate Mean sale of his company using Python. How can he accomplish this? [1]
Answer:
statistics.mean()
(b) How is data stored in DRAM ? [2]
Answer:
DRAM consists of a transistor and capacitor that’s capable of storing an electric charge. Depending on
the switching action of the transistor, the capacitor either contains no charge (0 bit) or does hold charge (1 bit).
(c) What is private browsing? [3]
Answer:
Browsing internet without revealing the search history and sharing your data is called private browsing. Private browsing can be accomplished in following ways.
1. Incognito browsing – It opens up a version of the browsers that does not track user activity. It is useful while entering sensitive data like bank details, etc. Private browsers or search engines like Duck Duckgo can also be used.
2. Proxy acts as a middleman between the computing device and the website. The backing website will get the 11’ address and information of the proxy site.
Question 4.
(a) In dictionaries, each key is separated from its value by ………………………. [1]
Answer:
Colon (:)
(b) Give the output of following Python codes:[2]
x = “Marvellous”
print (x[3:], “and”, x[:2])
print(x[-7:], “and”, x[- 4:-2])
print(x[2:7], “and”, x[-4:-1]
Answer:
vellous and Ma
vellous and lo
rvell and lou
(c) What are some important features of dictionaries? [4]
OR
Write a python program to find the name of the students scoring minimum and maximum marks. The student’s names and marks obtained are stored as key value pair in a dictionary named marksobt. Print name along with marks obtained.
Answer:
Some important features of dictionaries are:
(i) Each key maps to a value.
(ii) Keys within a dictionary are unique.
(iii) The values are mutable but the keys are immutable.
(iv) Dictionary, as a whole, is mutable.
OR
max_marks= max(marksobt.values())
print ("list of students scoring maximum")
max_name = [key for key in marksobt if marksobt[key] ==max_marks]
print (max_name, str (max_marks, ))
min_marks =min(marksobt.values())
print ("list of students scoring minimum")
min_name = [key for key in marksobt if marksobt[key] ==min_marks]
print (min_name, str (min_marks, ))
Question 5.
(a) Draw a flowchart to generate the Fibonacci Series as 1, 1, 2, 3, 5, 8…. terms. [3]
Where N is the number of terms given by the user.
Answer:
Commonly Made Error:
Students must make use of accurate symbols.
Answering Tip:
Fibonacci series is a series of numbers where in each number is the sum of the two preceding numbers. E.g. Fibonacci series is 1, 1, 2, 3, 5, 8, etc.
(b) Define the following terms with examples: [3]
(i) Word processing packages
(ii) Spreadsheet packages
(iii) DBMS packages.
OR
What do you mean by multitasking operating system?
Answer:
(i) Word processing software: It is a software that processes textual matter created to organize an error free document. Some popular word processing software are OO writer, MS-WORD, Google Docs, etc.
(ii) Spreadsheet software: It is a software package that accepts data in a tabular form i.e., in rows and columns and allows the user to manipulate, calculate, edit and analyze the data in the required manner. Some popular spreadsheet software are, MS-Excel, Quattro Pro, Google Sheets etc.
(iii) Data Base Management Software (DBMS): A DBMS is a software which manages the different database
with bulk information in the form of data. It can manage, add, delete and modify the database. Examples : Oracle, FOXBase, SYBase, Dbase IV & MS-Access etc.
OR
Multitasking term used in a modern computer system. It is a logical extension of a multiprogramsystem that enables the execution of multiple programs simultaneously. In an operating system, multitasking allows a user to perform more than one computer task simultaneously. Multiple tasks are also known as processes that share similar proresources like a CPU. The operating system keeps track of where you are in each of these jobs and allows you to transition between them without losing data. There are mainly two types of multi These are as follows:
(i) Preemptive Multitasking
(ii) Cooperative Multitasking
Question 6.
(a) Write a program to calculate simple interest. [2]
Answer:
principal = float (input (“Enter the principal amount”))
years = float (input (“Enter the no . of years”))
rate = float (input (“Enter rate of interest”))
si = (principal * years * rate))/100
print (“Simple Interest=”, si)
Commonly Made Error:
The student must provide accurate inputs.
Answering Tip:
The formula to calculate simple interest is SI = PTR/100 where P=Principal amount T = Time Period and R = Rate of Interest.
(b) What are data types? What are Python’s data type? [2]
Answer:
To represent real-life data, programming languages offer ways to handle them. These are called data types.
Python’s data types are:
- Numbers
- String
- List
- Tuple
- Dictionary
(c) How will you run a simple program in IDLE? [4]
Answer:
In script mode, we type Python program in a file and then use the interpreter to execute the content from the file. Working in interactive mode is convenient for beginners and for testing small pieces of code, as we can test them immediately. But for coding more than few lines, we should always save our code so that we may modify and reuse the code.
- First go to File → New File
- We can see a blank window popping up
- Write the python code.
- Save it with “.py” extension
- Execute by pressing Shift + F5 key or Run option
- Verify the output.
Question 7.
(a) We should share our password with everyone. [1] .
(True/False)
Answer:
False
(b) Discuss the three forms of PC Intrusion. [3]
OR
What do you understand by Net Ettiquetes? Explain any two such ettiquetes.
Answer:
PC Intrusion can occur in the following three forms:
- Sweeper Attack: In this attack, the hacker sweeps the PC’s complete data and files using a malicious program.
- Denial of Service: In this attack, the hackers make use of software that gains access to all the system resources so that other applications cannot access them. Hence, bringing the system to a halt.
- Password guessing: In this attack, hackers try to crack password of a system to break into it and then use the information stored for causing substantial damage.
OR
Net etiquettes refer to the proper manners and behaviour we need to exhibit while being online. These include:
1. No copyright violation: We should not use copyrighted materials without the permission of the creator or owner. We should give proper credit to owners / creators of open source content when using them.
2. Avoid cyber bullying: Avoid any insulting, degrading or intimidating online behaviour like repeated posting of rumours, giving threats online, posting the victim’s personal information, or comments aimed to publicly ridicule a victim.
Question 8.
(a) Ms. Reema will be teaching her students some techniques for problem solving today. Name these techniques. Which of these is a pictorial technique and which one is closer to a HLL program? [2]
Answer:
The techniques she will be teaching are algorithms, Flowchart and Pseudocodes,
Flowchart is a pictorial technique and Pseudocodes are closer to a HLL program.
(b) Variable is a name that is used to refer to memory location. Python variable is also known as an identifier and used to hold value. In Python, we don’t need to specify the type of variable because Python is a infer language and smart enough to get variable type. Variable names can be a group of both the letters and digits, but they have to begin with a letter or an underscore.
1. Which one of the following is correct way of declaring and initialising a variable, x with value 5?
(A) intx=5
(B) intx=5
(C) x=5
(D) declare x=5
Answer:
(C) x=5
Explanation:
The correct way of declaring and initialising a variable with value is Variable_name= value, eg x = 5.
2. Which of the following is not valid variable name in Python? [2]
(A) _var
(B) varname
(C) var11
(D) 11var
Answer:
(D) 11var
Explanation:
11var is not valid variable name in python, because variable name should not start with any number of special character expect (_) underscore.
(c) E-waste is becoming one of the fastest growing environmental hazards in the world today. If it is not properly treated or disposed of it can cause serious health hazards.
1. What is E-waste?
2. Name two hazards posed by e- waste.
3. Name an organization responsible for e-waste management.
4. What are the three r’s of E- waste management? [4]
Answer:
1. The electronic products that are no longer in use and end up in a landfill are called e-waste.
2. waste poses hazard to environment and health of living forms.
3. Central Pollution Control Board(CPCB)
4. Reduce, Reuse and Recycle.
Question 9.
(a) Convert the for loop into while loop. [2]
for x in range (8, 24, 4):
print (x)
Answer:
x = 8
while (x < 24)
print (x)
x += 4
(b) Write a program that reads a string and then capitalizes every other letter in the string, for example computer becomes computer. [5]
Answer:
string=input("Enter a string: ")
length=len(string)
print("Original String:", string)
string2= " "
for a in range(0, length):
if a%2 = = 0:
string2 += string[a]
else:
string2 += string[a].upper( )
print(string2)
Question 10.
What does e-waste comprise of ? [2]
Answer:
- E-waste includes scraps (copper, steel, plastic etc.) and the material which is dumped after reuse or recycling operations.
- It contains toxic pollutants like mercury, lead cadmium, chromium and plastics, (iii) These also contain valuable substances like gold, silver and copper.