Students must start practicing the questions from CBSE Sample Papers for Class 11 Informatics Practices with Solutions Set 1 are designed as per the revised syllabus.
CBSE Sample Papers for Class 12 Informatics Practices Set 1 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) The _______ components of a computer are called hardware. [1]
(A) Physical
(B) Logical
(C) Application
(D) None of these
Answer:
(A) Physical
Explanation: Computer hardware is the physical components that a computer system requires to function. [1]
(ii) Which of the following character is used to give single-line comments in Python? [1]
(A) //
(B) #
(C) !
(D) /*
Answer:
(B) #
Explanation: To write single-line comments in Python use the Numeric sign (#) at the beginning of the line. To write multi-line comments, close the text between triple quotes.
Example: “”” comment
text “”” [1]
(iii) The tuple in the table is related to: [1]
(A) Single row of the table
(B) Single column of the table
(C) Name of table
(D) None of these
Answer:
(A) Single row of the table
Explanation: A row in a table is termed as a tuple [1]
(iv) For which attribute fixed length string is suitable? [1]
(A) Salary
(B) City
(C) Gender
(D) Age
Answer:
(C) Gender
Explanation: Gender can be specified by a single letter M or F, so a fixed length string can be used. [1]
(v) _______ is a system that allows a group of connected computers to maintain a single updated and secure ledger which is updated only after all the nodes in the network authenticate the transaction. [1]
(A) P2P
(B) Client Server
(C) DBMS
(D) Blockchain
Answer:
(D) Blockchain
Explanation: Block chain is a system that allows a group of connected computers to maintain a single updated and secure ledger which is updated only after all the nodes in the network authenticate the transaction. [1]
Question 2.
(a) Find the primary memory from the following.
RAM, DVD, Magnetic Tape, PROM, Memory Card. [1]
Answer:
RAM, PROM. 1
Commonly Made Error:
Some students get confused in primary memory and secondary memory and don’t differentiate between them.
Answering Tip:
DVD, Magnetic tape, Memory card are secondary memory which have more space than primary memory.
(b) Suppose there is a computer with RAM but no secondary memory. Can we install software on that computer? [2]
Answer:
No, we cannot install any software on a computer with RAM without secondary memory. This is because loading software means storing the software permanently on computer’s memory but RAM is temporary. Also for loading a software large amount of memory space is required and RAM has very less storage capacity. [2]
(c) What security threats are involved when we throw away electronic gadgets that are non-functional? [2]
Answer:
The security risk will increase if the electronic and magnetic stripped cards are not disposed without a proper disposing process (like cutting the cards before throwing it). The hackers can take the advantage of this and can use these to hack anyone easily and retrieve sensitive or personal data to use it for their own benefits. [2]
(d) Briefly write about the functionality of each component. [4]
OR
What is specific purpose application software? Also, differentiate between system software and application software. [4]
Answer:
Functions of each computer are:
(i) Input Device: It accepts the instructions and data from the user. It converts these instructions and data in computer acceptable form because a computer can understand only binary symbols.
(ii) Output Device: This device sends the processed result to the user. It is mainly used to display the desired result to the user as per instructions.
(iii) Central Processing Unit: It consists a set of registers, arithmetic logic unit and control unit which together interprets and executes instructions in assembly language. The CPU consists of following main sub-systems as:
• Arithmetic Logic Unit (ALU): It contains the electronic circuitries that execute all arithmetic and logical operations on the available data.
• Control Unit (CU): It coordinates with the input and output devices of a computer.
(iv) Memory: It stores the data and instructions required during the processing of data and output results. Memory is classified into two categories as:
• Primary memory
• Secondary memory [4]
OR
Specific purpose application software is a type of software created to execute one specific task. Specific softwares are needed these days as all the works are divided into stages. So, all the works of different stages need different software for the proper functioning of that work. These softwares target a very narrow solution to a specific problem. [4]
| System Software | Application Software |
| System software is the type of software which is the interface between application software and computer system | Application software is the type of software which runs as per user request. It runs on the platform which is provided by system software |
| System softwares are installed on the computer when operating system is installed. | Application softwares are installed according to users requirements. |
Question 3.
(a) What are string literals, how can they be created? [1]
Answer:
(a) String literals are fixed value data terms. They can be created by using single quote or double quotes.
e.g. “Aryan”, “Welcome” etc. [1]
(b) In which, membership operators are used? [1]
Answer:
Membership operators are used in lists, tuples, strings, etc. [1]
(c) Write the output of the given Python code: [1]
list1 = [‘physics’, ‘chemistry’, 1997,2000]
list2 = [1,2, 3,4,5,6, 7]
print (“List1[1 : 5]”, list2[1: 5])
Answer:
List2[1: 5]: [2, 3, 4, 5] [1]
(d) Are lists mutable or immutable? [1]
Answer:
Lists are mutable. [1]
Commonly Made Error:
Some students get confused in mutable and immutable.
Answering Tip:
The elements of list can be changed after creation because it is mutable.
(e) When are dictionaries more useful than lists? [2]
OR
Write a module to calculate and display the sum of all odd numbers in a list. [2]
Answer:
Dictionaries can be much more useful than lists. For example : suppose we wanted to store all our friend’s cell phone numbers then we could create a list of pairs (phone number, name), but once this list becomes long enough searching this list of a specific phone number will get time consuming. It is better if we could index the list by our friend’s name. This is precisely what a dictionary does. [2]
OR
pos = 0
sum = 0
l = [ ]
while pos < len (l):
if l [pos] % 2 ! = 0:
sum = sum + l [pos]
pos + = 1
(f) Write short note on Python Dictionaries? [4]
Answer:
Dictionary is a data type in Python which stores the data in key value pair. Each key value pair is separated by comma. While each key with its corresponding value is given by colon (:), key value pairs are shown in curly brackets in dictionaries. Keys of a dictionary are immutable. Syntax
dictionaryName = {key 1: value 1, key 2: value 2,…}
e.g., dic 1 = {“Colour”: “Blue”, “Fruit”: “Mango”, “Price”: 100}
below is the relationship between key value pair of above dictionary
| Key-Value pair | Key | Value |
| “Colour”: “Blue” | “Colour” | “Blue” |
| “Fruit”:”Mango” | “Fruit” | “Mango” |
| “Price”: 100 | “Price” | 100 |
Dictionaries are also called “associative arrays” or “mapping” or “hashes”.
A dictionary operation that takes a key and finds the corresponding value is called “lookup”. [4]
Question 4.
(a) Help Kiyaan in predicting the output of the following queries: [3]
(i) SELECT (15/3+6*2-1) AS ‘FINAL’;
(ii) SELECT (16%3+5*2) AS ‘RESULT’;
(iii) SELECT (5*8/4+3) AS’PRINT’;
Answer:
(i) FINAL 16
(ii) RESULT 11
(iii) PRINT 13 [3]
(b) Write command to create database School in which create table Student whose fields are: [3]
| RollNo | int |
| Name | char |
| Class | varchar |
| Address. | varchar |
| Section | int |
| RegistrationID | Varchar |
Answer:
CREATE DATABASE School;
CREATE TABLE Student
(RollNo int primary key,
Name char(20),
Class varchar(10),
Address varchar(30),
Section int,
RegistrationID Varchar(10)
); [3]
(c) What do you mean by VARCHAR? [3]
Answer:
VARCHAR specifies character type data of length where n could be any value from 0 to 65535. But unlike CHAR, VARCHAR(n) is a variable- length data type. That is, declaring VARCHAR (30) means a maximum of 30 characters can be stored but the actual allocated types will depend on the length of entered string. So ‘city’ in VARCHAR (30) will occupy space needed to store 4 characters only [3]
(d) Explain SELECT command with an example. [4]
Answer:
SELECT command is used to retrieve the sub part of rows or columns from one or more tables.
Syntax
SELECT column_name FROM Table_name;
| Emp_Code | Emp_Name | Designation | Salary | Joining_Date |
| 1001 | Rahul | Accountant | 25000 | 2011-5-25 |
| 1002 | Krishna | Clerk | 20000 | 2010-6-19 |
| 1003 | Akshat | Accountant | 22000 | 2012-7-22 |
| 1004 | Apoorvi | Clerk | 18000 | 2013-3-17 |
| 1005 | Nishant | Supervisor | 24000 | 2016-4-23 |
| 1006 | Sonam | Accountant | 22000 | 2010-5-24 |
| 1007 | Pihu | Manager | 38000 | 2012-6-18 |
SELECT Emp_Name FROM Employee;
Output:
| Rahul |
| Krishna |
| Akshat |
| Apoorvi |
| Nishant |
| Sonam |
| Pihu |
If you want to display the details of all employee, asterisk * is used.
Syntax
SELECT*FROM Table name;
e-g
SELECT* FROM Employee;
5. (a) What are the possible values for BOOLEAN data field? [1]
OR
Which of the following is not a valid SQL data type?
DECIMAL, FLOAT, CHARACTER, NUMERIC
Answer:
For a Boolean data field, two values are possible as 1 (True) and 0 (False) [1]
OR
DECIMAL
(b) What is the difference between CHAR and VARCHAR2 data type in SQL? [2]
Answer:
Both CHAR and VARCHAR2 are used for characters data type but varchar2 is used for character strings of variable length whereas char is used for strings of fixed length. [2]
(c) Given Employee table as follows
| Employee_Id | NAME | Commission |
| 101 | Prabhat Sharma | NULL |
| 102 | Divya Seth | 8900 |
| 103 | Arif Khan | NULL |
What values will the following statements returns?
(i) SELECT Name FROM Employee WHERE Employee_Id = 101;
(ii) SELECT Employee_Id FROM Employee WHERE Commission > 8500; [2]
Answer:
(d) Write the command to create table Student using following data:
| Column Name | Data typ |
| Studen_ID | Varchar (5) Primary key |
| Stu_Name | Char (20) |
| Subject | Char (20) |
| Marks | Integer |
| Address | Varchar (30) |
Answer:
CREATE TABLE student
(student_ID Varchar (5) Primary Key, Stu_Name char (20),
Subject char (20),
Marks Integer,
Address varchar (30)); [2]
(e) Consider the table Student given below where ID is primary key, write commands in SQL: [4]
| ID | Name | City | Stream | Percentage |
| 1201 | Amar Kumar | Lucknow | Science | 85 |
| 1202 | Dimpy Singh | Agra | Art | 80 |
| 1203 | Esha Chaturvedi | Kanpur | Art | 75 |
| 1204 | Himanshu Sharma | Agra | Art | 87 |
| 1205 | Shyam Yadav | Lucknow | Science | 90 |
(i) Display the student name and stream who lives in Lucknow.
(ii) Display the student ID and name whose percentage is greater than 80.
(iii) Display the student names who is from Art Stream and whose percentage is less than 80.
(iv) Display all the details of students.
Answer:
(i) SELECT Name, Stream FROM Student where City= “Lucknow”;
(ii) SELECT ID, Name FROM Student where Percentage>80;
(iii) SELECT Name from Student where Stream= ‘Art AND Percentage<80;
(iv) SELECT * from Student; [4]
(f) Explain hierarchical model in DBMS. [4]
Answer:
A hierarchical model represents the data in a tree-like structure in which there is a single parent for each record. To maintain order there is a sort field which keeps sibling nodes into a recorded manner. These types of models are designed basically for the early mainframe database management systems, like the Information Management System (IMS) by IBM.
This model structure allows the one-to-one and a one-to-many relationship between two/ various types of data. This structure is very helpful in describing many relationships in the real world; table of contents, any nested and sorted information. [4]
Question 6.
(a) What are mutable object and immutable object? [2]
Answer:
Mutable objects are those that allow and support changes in their contents. The mutable types include lists and dictionaries. It means that no new value object is created rather changes are made in the same value object. Immutable objects are those that can never change their value. In Python, integer is immutable. [2]
(b) What is the error in following Python program with one statement?
Print (“My favourite subject is”, subject)
Answer:
Given statement is trying to print the value of subject which is undefined variable name. Before to print the value of subject, you must define the variable subject. [2]
(c) Find the output of the following questions based on given dictionary
Employee = {“Name’ , : ‘Rakesh’ , ‘Dept’ : ‘Accountant’ , ‘Salary’ : 25000}
Answer:
(i) dict_keys([‘Name’, ‘Depth ‘Salary’])
(ii) dict_values([‘Rakesh’, ‘Accountant, 25000])
(iii) {‘Name’ : ‘Rakesh’, ‘Dept: ‘Account, ‘Salary’ : 25000, ‘Age’ : 25}
(iv) ‘Accountant’
(v) ‘Rakesh’
(vi) 3 [3]
(d) Write a program to print sum of first n natural numbers. [3]
Answer:
n = int (input(“Enter the number “)) sum = 0
for i in range (1, n + 1) :
sum + = n
print (“sum of first “, n, “natural number is “, sum) [3]
7. (a) Explain Internet of Things (IoT). [2]
Answer:
• IoT refers to the billions of physical devices around the world that are now connected to the Internet.
• It is a giant network of connected things and people all of which collect and share data about the way they are used and about the environment around them.
• IoT exploits recent advances in software, falling hardware prices and modern attitudes towards technology. It’s new and advanced elements bring major changes in the delivery of products, goods and services; and the social, economic and political impact of those changes.
• IoT makes areas of improvement clear. Current analytics gives us superficial insight but IoT provides real world information leading to more effective management of resources. [2]
(b) Differentiate between public cloud and private cloud. [2]
Answer:
| Public cloud | Private cloud |
| Cloud Computing infrastructure is shared with the public by service providers over the internet. It supports multiple customers i.e., enterprises | Cloud Computing infrastructure is shared with private organizations by service providers over the internet. It supports one enterprise |
| Cloud service provider manages the cloud and customers use them. | Managed and used by a single enterprise. |
Case Based Questions (Attempt any 4)
Question 8.
Consider the following dictionary in Python:
Book={“Name”: “Information Technology”, “Price”: 560, “Author”: “Dr. D.S. Yadav”, “Pages”: 480, “Year” : 1998)
(i) Print(Book.get(“Price”)) displays:
(A) 560
(B) Invalid statement
(C) ‘Price’:560
(D) None of these
Answer:
(A) 560
(ii) Print(Book.get(480)) displays:
(A) ‘pages’
(B) Error
(C) ‘Pages’:480
(D) None of these
Answer:
(B) Error
(iii) Print(Book[‘Name’]) will return the value:
(A) 23
(B) 22
(C) 2
(D) Error
Answer:
(B) 22
(iv) The statement Book[“New Age”]= “Publisher” will:
(A) Generate error
(B) Add new element into dictionary as (‘New Age’: ‘Publisher’)
(C) Add new element into dictionary as (‘Publisher’: ‘New Age’)
(D) None of these
Answer:
(B) Add new element into dictionary as (‘New Age’: ‘Publisher’)
(v) The statement Book.clear( ) will:
(A) clear is not function of dictionary
(B) delete first key and value from the dictionary
(C) Clear all the data from the dictionary Book
(D) None of these
Answer:
(A) clear is not function of dictionary