Students must start practicing the questions from CBSE Sample Papers for Class 11 Informatics Practices with Solutions Set 10 are designed as per the revised syllabus.
Recommended Reading On: Computer MCQ Questions for Class 8 with Answers
CBSE Sample Papers for Class 12 Informatics Practices Set 10 with Solutions
Time Allowed: 3 hours
Maximum Marks: 70
General Instructions:
- All questions are compulsory.
- Answer the questions after carefully reading the text.
- Student has to answer only one question where choice is given.
- All programming questions have to be answered with respect to Python only.
- In Python indentation is mandatory; however, number of spaces used for indenting may vary.
- In SQL related questions – semicolon should be ignored for terminating the SQL statements.
- Use of calculators is not permitted.
SOLVED
Multiple Choice Question:
Question 1.
(i) Information and data enter into a computer is called _________.
(A) INPUT
(B) OUTPUT
(C) INSERT
(D) None of these
Answer:
(A) INPUT
Explanation: Any information or data sent to a computer for processing is considered as input. [1]
(ii) Which property of a relation is used to represent number of columns?
(A) Key
(B) Attribute
(C) Degree
(D) Cardinality
Answer:
(C) Degree
Explanation: Number of columns is number of attributes, and the number of attributes is the degree of a relation. [1]
(iii) Which of the following is not the mode of interacting with python?
(A) Interactive Mode
(B) Script Mode
(C) Hybrid Mode
(D) None of these
Answer:
(C) Hybrid Mode
Explanation: Python has two basic modes: script and interactive. The normal mode is the mode where the scripted and finished .py files are run in the Python interpreter. Interactive mode is a command line shell which gives immediate feedback for each statement, while running previously fed statements in active memory [1]
(iv) Which command is used to insert a new record in a table ?
(A) ADD
(B) INSERT INTO
(C) INSERT
(D) NEW
Answer:
(B) INSERT INTO
Explanation: The three update commands INSERT, DELETE, UPDATE are used to place and remove values in a table. [1]
(v) _______ is a subsystem of Artificial Intelligence, wherein computers have the ability to learn from data using statistical techniques, without being explicitly programmed by a human being. [1]
(A) Machine Learning
(B) Natural Language
(C) Statistical Learning
(D) Virtual Reality
Answer:
(A) Machine Learning
Explanation: Machine learning is the study of computer algorithms that can improve automatically through experience and by the use of data. It is seen as a part of artificial intelligence. [1]
Question 2.
(a) What is computer? [1]
Answer:
Computer is an electronic device which manipulates the data according to the list of instructions. [1]
(b) Define the term EEPROM. [2]
Answer:
EEPROM stands for Electrically Erasable Programmable ROM. It is similar to EPROM, but it can be erased and then rewritten electrically and the burning process is reversible by exposure to electric pulses. It is the most flexible type of ROM and it now commonly used for holding BIOS. [2]
(c) What do you mean by software? [2]
Answer:
Software is a set of computer programs, procedures and associated documentation concerned with the operation of a data processing system. Software, commonly known as a set of programs, consists of all the required instructions that tell the hardware how to perform a particular task. Software is not only the basic requirement of a computer system but it makes a computer more powerful and useful. [2]
(d) What are the functions of a computer? [4]
OR
How much power does a computer use? [4]
Answer:
Computer performs four basic functions which are as follows:
(i) Input: Information or data that is entered into a computer is called input. It sends data and instruction to the Central Processing Unit (CPU).
(ii) Processing: It is the sequence of actions taken on data to convert it into information which is meaningful to the user. It can be calculation, comparisons or decisions taken by the computer.
(iii) Output: It makes processed data available to the user. It is mainly used to display the desired result to the user as per input instructions.
(iv) Storage: It stores data and programs permanently. It is used to store information during the time of program execution and possible to get any type of information from it. [4]
OR
The power consumption of a computer varies depending on whether it is a desktop or a laptop:
(i) Desktop Computer: It uses an average of 200 W/ hour. This is the sum of the average consumption per hour of the computer itself (171W), the internet modem (10W), the printer (5W) and the loudspeaker (20 W) Assuming that a computer is on for eight hours a day, the annual consumption comes to 600 kWh.
(ii) Laptop: It uses considerably less – power between 50 and 100W per hour that it is on, depending on the model. If it is used for eight hours a day, consumption therefore varies between 150 and 300 kWh/year.
(iii) On stand-by mode: The power consumption of both a desktop and a laptop computer falls to about a third. Putting the monitor on stand-by reduces its consumption by 15%. If the computer is switched off completely, then of course it does not use any power. [4]
Question 3.
(a) Python is based on which programming languages? [1]
Answer:
(a) Python is based on two programming languages
(i) ABC language
(ii) Module 3 [1]
(b) What are the logical operators of Python? [1]
Answer:
(b) OR, AND, NOT, are the logical operators in python. [1]
(c) What is the difference between / and // operator? [1]
Answer:
// is an integer or a floor division operator whereas / is a normal division.
e.g. 7.0//2 → 3.0
7.0/2 → 3.5 [1]
(d) Write the output from the following code,
x = 10
y = 20
if (x > y):
print (x + y)
else:
print (x – y)
Answer:
-10 [1]
(e) Write a program to print every character of a string entered by user in a new line using loop. [2]
OR
Find the value of following questions based on list value = [45,32,98, -78, -6, ‘Hello’, ‘Honesty’]
(i) value [5]
(ii) value [-5]
(iii) value [1] + value [-1]
(iv) value [4] + value [-4] [2]
Answer:
x=input(“Enter the string:”)
for i in x:
print(i)
Commonly Made Error:
Students forget to use semicolon at their proper place.
Answering Tip:
Semicolon is must after conditional statements as for, while, if, etc.
OR
(i) Hello
(ii) 98
(iii) TypeError : unsupported operand type (s) for +’int’ and ‘str’
(iv) -84 [2]
(f) Write a Python program to enter the list and display the frequency of element using dictionary. [4]
Answer:
list1 = [ ]
num = int(input (“Enter number of elements :”))
for i in range (0, num):
item = int (input( ))
listl.append (item)
print(“Original List :”, list1)
print (“Elements with frequency”)
freq = { }
for itm in list1 :
if (itm in list1):
freq[itm] + = 1
else:
freq[itm] = 1
for key, value in freq, item( ):
print(“%d: %d” %(key, value)) [4]
Question 4.
(a) Why foreign keys are allowed to have NULL values ? Explain with an example. [3]
Answer:
In some cases, foreign key can take NULL value if it is not the part of primary key of the foreign table. This is because the foreign key is used to represent a relationship between two relations and its value is derived from primary key of another relation. Hence, it may or may not have all values of primary key of other relation. [3]
(b) What are the limitations of file system that can be overcome by a relational DBMS? [3]
Answer:
There are various limitations of file system that can be overcome by a relational DBMS as:
- Data redundancy and inconsistency
- Difficulty in accessing data
- Integrity problem
- Atomicity problem
- Concurrent access anomalies
- Security problems
- Data isolation [3]
(c) Define the following: [3]
(i) Data item
(ii) Record
(iii) Table
Answer:
(i) Data item: The smallest unit of named data is called data item. It represents one type of information and is also referred to as a field.
(ii) Record: A named collection of data items that represent a complete unit of information is called a record.
(iii) Table: A group of all logically related records that are given a name is called a table [3]
(d) Define data model and also explain its types. [4]
Answer:
Data model is a collection of conceptual tools for describing data, data relationship, data semantics and consistency constraints. There are three different data models as:
(i) Hierarchical model: It organizes the records as a collection of trees rather than arbitrary graphs. It represents a hierarchy of parent and child data segments.
(ii) Network model: Data are represented by collection of records. Relationships among data are represented by links. Organization is information arbitrary graph.
(iii) Relational model: Data and relationship are represented by a collection of tables. Each table has a number of columns with unique names, e.g. customer, account. It represents a hierarchy of parent and child data segments. [4]
Commonly Made Error:
Hierarchical model and relational models seem similar to many students.
Answering Tip:
Try to explain various model architecture with the help of diagrams.
Question 5.
(a) What is data? [1]
OR
Give any two examples of DBMS. [1]
Answer:
Data means known facts that can be recorded and have some implicit meaning. [1]
OR
ORACLE and SQL [1]
(b) Define conceptual level. [A|T] [2]
Answer:
> Next highest level of abstraction.
> Describes what data are stored.
> Describes the relationship among data.
> Database administrator level
Commonly Made Error:
Some students got confused in level of DBMS.
Answering Tip:
There are 3 levels of DBMS, conceptual level, physical level and view level.
(c) What is SQL? [2]
Answer:
SQL (Structured Query Language) is a database tool which is used to create and access database to support software application. [2]
(d) Help Ayus in predicting the output of the following queries: [2]
(i) SELECT (2*5+3-2) AS ‘RESULT’;
(ii) SELECT (5*9%6) AS ‘OUTPUT’;
Answer:
(i) RESULT 11
(ii) Output 3 [2]
(e) Give the output of the following SQL Statements based on table GRADUATE:
| NAME | STIPEND | SUBJECT | AVERAGE | DIV |
| 1. Karan | 400 | Physics | 68 | I |
| 2 Diwakar | 450 | Comp Sc. | 68 | I |
| 3. Divya | 300 | Chemistry | 62 | I |
| 4. Rekha | 350 | Physics | 63 | I |
| 5. Arjun | 500 | Maths | 70 | I |
| 6. Sabina | 400 | Chemistry | 55 | II |
| 7. John | 250 | Physics | 64 | II |
| 8. Robert | 450 | Maths | 68 | I |
| 9. Rubina | 500 | Comp Sc. | 62 | I |
| 10. Vikas | 400 | Maths | 57 | I |
(i) SELECT NAME FROM GRADUATE WHERE AVERAGE > =70;
(ii) SELECT NAME, SUBJECT FROM GRADUATE WHERE DIV = II;
(iii) SELECT SUBJECT FROM GRADUATE WHERE STIPEND = 450;
(iv) SELECT S NO, NAME FROM GRADUATE WHERE SUBJECT = “Comp Sc”; [4]
Answer:
(i) Arjun
(ii)
Sabina Chemistry
Vikas Maths
(iii)
Comp Sc. Maths
(iv)
2 Diwakar
9 Rubina [4]
(f) What do you mean by DBMS? [4]
Answer:
DBMS (Database Management system) is a collection of program that enables users to create and maintain a database. The database is a general purpose system that facilitates the process of defining, constructing, manipulating and sharing data base among various users & application, e.g. ORACLE, MS-ACCESS, FOXPRO, SQL, etc.
The goal of a DBMS is to provide an environment that is both convenient and efficient use in
> Retrieving information from the database
> Storing information into the database. [4]
Question 6.
(a) Rewrite the following code in Python after removing all syntax errors. Underline each correction done in the code.
for Name in [Amar, Shweta, Parag]
If Name[0] = ‘s’:
print(Name) [2]
Answer:
for Name in [ “Araar”, “Shweta” , “Parag” ] :
if Name [0] = = ‘s’ :
print (Name)
Commonly Made Error:
Sometimes students forget to use colon and proper indentation.
Answering Tip:
Use proper indentation in the next line of for and if statements.
(b) What are Python data types? Explain any one data type. [3]
Answer:
Python data types are used to define the type of a variable. Any values that represent in quotes are string data type. Number without decimal point is integer data type. Python has 5 data types as
- Numeric
- String
- List
- Tuple
- Dictionary
Numeric data types
This data type is used to hold numeric value. Like other languages C++, Java, etc, there is no need to declare data types with variables. You can simply assign values to the variables. But if you want to know the type of variable, type ( ) method is used.
Number data types includes following:
> int includes signed integers without fractional part. It can be positive or negative, e.g. 245, – 75, etc
> long includes long integers of non-limited size. e.g. 437L, 531. This data type exists in Python 2.x, deprecated in Python 3.x.
> float includes floating precision numbers, e.g. 453-3,43.0, 834.34, etc.
> complex includes complex numbers which
are in form of a + bj. Here, a is real number and b is the imaginary number. [3]
(c) Write the following mathematical equation in Python expression
- \(3 x^3+4 x^2+5 x+7\)
- \(y=\frac{a+b+c}{3}\)
- \(a=\frac{1}{2}(a+b) \times h\)
Answer:
(i) 3*(x**3) + 4*(x**2) + 5*x + 7
(ii) y = (a + b + c)/3
(iii) \(a=\frac{1}{2} *(a+b)^* h\) [3]
(d) What is the difference between triple quoted multiline string and a multiline string with backslash (\) ? [2]
Answer:
Triple quoted multiline strings also counts End Of Line (EOL) characters in the size of the string whereas the multiline strings with backslash (\) at the End Of Line does not count backslash ( \) as the size of the string. [2]
Question 7.
(a) Write one benefit of using cloud services. [2]
Answer:
One benefit of using cloud computing services is that firms can avoid the up front cost and complexity of owning and maintaining their own IT infrastructure and instead simply pay for what they use, when they use it.
(b) Define Smart Cities. [2]
Answer:
Smart city is a framework, predominantly composed of Information and Communication Technologies to develop, deploy and promote sustainable development practices to address growing urbanization challenges. Smart cities affect everyone whether directly or indirectly [2]
Case Based MCQs (Attempt Any 4)
Question 8.
Expressions in programming are like formulas in mathematics: both use values (in Python literals and names bound to values) to compute a result. But unlike mathematics, expressions in Python can compute results of a wide variety of types (e.g., Boolean and string) not just mathematical results.
We classify these operators, both symbols and identifiers, into four categories and examine them separately: Arithmetic (+ -* III % **), Relational: (== != <><= >= is in), Logical (and not or), and finally Bitwise (& | ~ ^ <<>>) When two or more operators share an operand with the same precedence, such as a * b / c, the expression is evaluated according to associativity.
When all of the operators in an expression have the same precedence, the expression is evaluated using left to right associativity. Now, since the ** operator has right-to-left associativity, a ** b ** c will be evaluated as a * * b ** c. For exponentiation, the expression on the right is evaluated first. On the other hand, since the * operator has left-to right associativity, a * b * c is treated as (a * b * c [4]
For multiplication, the expression on the left is evaluated first.
(i) A python expression contains:
(A) Only Operator
(B) Only Operands
(C) both Operators and Operands
(D) None of these
Answer:
(C) both Operators and Operands
(ii) If a =1 and b =2 and c =3 then a **b ** c evaluate to:
(A) 1
(B) 8
(C) 9
(D) 15
Answer:
(A) 1
(iii) If a= 3 and b = 5 then ( a > b and b>(A) evaluate to:
(A) True
(B) False
(C) True and True
(D) None of these
Answer:
(B) False
(iv) % is known as the modulus operator and if a =13 and b =2 then a % b evaluate to _____.
(A) 0
(B) 6
(C) 1
(D) None of these
Answer:
(C) 1
(v) Out of following which is not a bit wise operator:
(A) <<
(B) >>
(C) &
(D) >=
Answer:
(D) >=