Class 12 Computer Science Sample Paper 2024

CBSE Class 12 Computer Science Sample Paper 2024

Time allowed: 3 Hours Maximum Marks: 70

General Instructions:
Please check this question paper contains 35 questions.

• The paper is divided into 5 Sections- A, B, C, D and E.
• Section A, consists of 18 questions (1 to 18). Each question carries 1 Mark.
• Section B, consists of 7 questions (19 to 25). Each question carries 2 Marks.
• Section C, consists of 5 questions (26 to 30). Each question carries 3 Marks.
• Section D, consists of 2 questions (31 to 32). Each question carries 4 Marks.
• Section E, consists of 3 questions (33 to 35). Each question carries 5 Marks.
• All programming questions are to be answered using Python Language only.

Section-A (18 Marks)

1. Which of the following is an invalid identifier to be used in Python?
a) per%marks
b) _for
c) While
d) true

2.What is the correct way to add an element to the end of a list in Python?
a) list.add(element)
b) list.append(element)
c) list.insert(element)
d) list.extend(element)

3. What will be the output of print(“Welcome To My Blog”[2:6] + “Welcome To My Blog”[5:9])
a) Lcomme
b) lcomme T
c) lcomme To
d) lcomme

4. Which of the following statements is false?
a) A try-except block can have more than one except statement
b) One block of except statement cannot handle multiple exceptions
c) The finally block is always executed
d) When 1 == “1” is executed, no exception is raised

5. Which of the following statement(s) would give an error during the execution of the following code?

R = {‘pno’:52,’pname’:’Virat’, ‘expert’:[‘Badminton’,’Tennis’] ,’score’:(77,44)}
print(R) #Statement 1
R[‘expert’][0]=’Cricket’ #Statement 2
R[‘score’][0]=50 #Statement 3
R[‘pno’]=50 #Statement 4

a)  Statement 1
b) Statement 2
c) Statement 3
d) Statement 4

6. Which pickle module method is used to write a Python object to a binary file?
a) save()
b) serialize()
c) store()
d) dump()

7. Given the following dictionaries
dict_student = {“rno” : “53”, “name” : ‘Rajveer Singh’}
dict_marks = {“Accts” : 87, “English” : 65}
Which statement will append the contents of dict_marks in dict_student?
a)  dict_student + dict_marks
b) dict_student.add(dict_marks)
c)  dict_student.merge(dict_marks)
d) dict_student.update(dict_marks)

8. Which of the following is not a component of the math module in Python?
a) ceil()
b)  mean()
c) fabs()
d)  pi

9. What will be the output of the following code?

L=[“One , Two”, “Three”, “Four”]
print(len(L)/2*len(L[0]))

a)  6.5
b)  13
c)  13.5
d) 6.0

10.  Expand the following terms:

(i) PPP
(ii) VoIP

Class 12 Computer Science Sample Paper 2024

11.  Which SQL operator performs pattern matching?
a)  BETWEEN operator
b)  LIKE operator
c)  EXISTS operator
d)  =

12. Which Python function is used for displaying only one result set from SQL table in a database?
a)  fetch1()
b)  fetchno()
c)  fetchall()
d)  fetchone()

13. Which of the following file opening mode in Python, generates an error if the file does not exist?
a) a
b) r
c) w
d)  w+

14. The correct syntax of seek() is:

a)  file_object.seek(offset [, reference_point])
b) seek(offset [, reference_point])
c) seek(offset, file_object)
d)  seek.file_object(offset)

15. Which of the following statements is false?

a) SMTP and POP protocols are used in email communication.
b) URL of a page is not always the same as its domain name.
c) HTTPS is safer than HTTP.
d) Interlinking of collection of webpages is called Internet.

16. Fill in the blank:
_________ protocol provides access to services hosted on a remote computer.
a)  FTP
b)  PPP
c) Telnet
d) SMTP

Q 17 and 18 are ASSERTION AND REASONING based questions.
Mark the correct choice as

(a) Both A and R are true and R is the correct explanation for A
(b) Both A and R are true and R is not the correct explanation for A
(c) A is True but R is False
(d) A is false but R is True

17 Assertion (A): For changes made to a variable defined within a function to be visible outside the function, it should be declared as global.
Reasoning (R): Variables defined within a function are local to that function by default, unless explicitly specified with the global keyword.

18 Assertion (A): A binary file in python is used to store collection objects like lists and dictionaries that can be later retrieved in their original form using pickle module.

Reasoning (A): Binary files are just like normal text files and can be read using a text editor like Notepad.

Section-B (14 Marks)

19. Write two advantages and two disadvantages of circuit switching.

OR

Differentiate between Web server and web browser. Write the names of any two web browsers.

20. Rewrite the following code in Python after removing all the syntax errors. Underline each correction done in the code.
num1, num2 = 10, 45
While num1 % num2 == 0
num1+= 20
num2+= 30
Else:
print(‘hello’)

Class 12 Computer Science Sample Paper 2024

21. Write a function dispBook (BOOKS) in Python, that takes a dictionary BOOKS as an argument and displays the names in uppercase of those books whose name starts with a consonant.

For example, Consider the following dictionary

BOOKS = {1:”Python”, 2:”Internet Fundamentals “, 3:”Networking “, 4:”Oracle sets”, 5:”Understanding HTML”}
The output should be:
PYTHON
NETWORKING

OR

Write a Python Program containing a function FindWord(STRING, SEARCH), that accepts two arguments : STRING and SEARCH, and prints the count of occurrence of SEARCH in STRING. Write appropriate statements to call the function.

For example, if STRING = “Learning history helps to know about history with interest in history” and SEARCH = ‘history’, the function should display The word history occurs 3 times.

22. What will be the output of the following code?
L = [5,10,15,1]
G = 4
def Change(X):
global G
N=len(X)
for i in range(N):
X[i] += G
Change(L)
for i in L:
print(i,end=’$’)

23. Write a suitable Python statement for each of the following tasks using built-in functions/methods only:

i) To delete an element Mumbai:50 from Dictionary D.

ii To display words in a string S in the form of a list

Or

Write a Python Program to display alternate characters of a string my_str.
For example, if my_str = “Computer Science” The output should be Cmue cec

24. Differentiate between % (percentage) and _(underscore) characters used with the LIKE operator in SQL with appropriate examples.

Or

Differentiate between DROP and DELETE commands in SQL with appropriate examples.

25. Consider the following two commands with reference to a table, named Employee having a column named Department:

(a) Select count(Department) from Employee;

(b) Select count(*) from Employee;

If these two commands are producing different results,

(i) What may be the possible reason?

(ii) Which command (a) or (b) might be giving a higher value?

Section-C (15 Marks)

26 (a) Consider the table, BOOK and MEMBER given below:

TABLE : BOOK

Table: MEMBER

What will be the output of the following statement?

SELECT * FROM BOOK NATURAL JOIN MEMBER;

(b) Write the output of the queries (i) to (iv) based on the table

Table: Employee

i) SELECT NAME, PROJECT FROM EMPLOYEE ORDER BY NAME DESC;

ii) SELECT NAME, SALARY FROM EMPLOYEE WHERE NAME LIKE ‘A%’;

iii) SELECT NAME, DOJ FROM EMPLOYEE WHERE SALARY BETWEEN 100000 AND 200000;

iv)SELECT * FROM EMPLOYEE WHERE PROJECT = ‘P01’;

27 (a) Consider the following tables – FACULTY and COURSES :

Table: FACULTY

Table: COURSES

What will be the output of the following statement?

i) SELECT FID, MIN(FEES), MAX(FEES) FROM COURSES GROUP BY FID;

ii) SELECT AVG(SALARY) FROM FACULTY WHERE FNAME LIKE ‘%a’;

iii) SELECT FNAME, CNAME FROM FACULTY F, COURSES C WHERE F.FID=C.FID AND COURSES.FID=’F04′;

iv) SELECT FNAME, CNAME , FEES FROM FACULTY F , COURSES C WHERE F.FID = C.FID AND FEE>15000;

(b) Write the name of the command to display the structure of a table in a database.

28. Write a function COUNT() in Python to read from a text file ‘Gratitude.txt’ and display the count of the letter ‘e’ in each line
Example: If the file content is as follows:

Gratitude is a humble heart’s radiant glow,
A timeless gift that nurtures and bestows.
It’s the appreciation for the love we’re shown,
In moments big and small, it’s truly known.

The COUNT() function should display the output as:
Line 1 : 3
Line 2 : 4
Line 3 : 6
Line 4 : 1

Or

Write a function Start_with_I() in Python, which should read a text file ‘Gratitude.txt’ and then display lines starting with ‘I’.
Example: If the file content is as follows:

Gratitude is a humble heart’s radiant glow,
A timeless gift that nurtures and bestows.
It’s the appreciation for the love we’re shown,
In moments big and small, it’s truly known.

Then the output should be

It’s the appreciation for the love we’re shown,
In moments big and small, it’s truly known.

29. Navdeep creates a table RESULT with a set of records to maintain the marks secured by students in Sem1, Sem2, Sem3, and their divisions. After the creation of the table, he entered data of 7 students in the table.

Based on the data given above answer the following questions:

i) Identify the columns which can be considered as candidate keys?

ii)  If 2 more columns are added and 3 rows are deleted from the table result, what will be the new degree and cardinality of the above table?

iii) Write a statement to increase the SEM2 marks by 3% for the students securing marks between 70 to 100.

Class 12 Computer Science Sample Paper 2024

30. Given a Dictionary Stu_dict containing marks of students for three test-series in the form Stu_ID:(TS1, TS2, TS3) as key-value pairs.

Write a Python program with the following user-defined functions to perform the specified operations on a stack named Stu_Stk

(i) Push_elements(Stu_Stk, Stu_dict) : It allows pushing IDs of those students, from the dictionary Stu_dict into the stack Stu_Stk, who have scored more than or equal to 80 marks in the TS3 Test.

(ii) Pop_elements(Stu_Stk): It removes all elements present inside the stack in LIFO order and prints them. Also, the function displays ‘Stack Empty’ when there are no elements in the stack. Call both functions to execute queries.

For example:

If the dictionary Stu_dict contains the following data:
Stu_dict ={5:(87,68,89), 10:(57,54,61), 12:(71,67,90), 14:(66,81,80), 18:(80,48,91)}

After executing Push_elements(), Stk_ID should contain
[5,12,14,18]

After executing Pop_elements(), The output should be:
18
14
12
5
Stack Empty
3
8

Section-D (8 Marks)

31. Create a function maxsalary() in Python to read all the records from an already existing file record.csv which stores the records of various employees working in a department. Data is stored under various fields as shown below:

Function should display the row where the salary is maximum.

Note: Assume that all employees have distinct salary.

32. Consider a binary file ‘INVENTORY.DAT’ that stores information about products using tuple with the structure (ProductID, ProductName, Quantity, Price). Write a Python function expensiveProducts() to read the contents of ‘INVENTORY.DAT’ and display details of products with a price higher than Rs. 1000. Additionally, calculate and display the total count of such expensive products.

For example: If the file stores the following data in binary format

(1, ‘ABC’, 100, 5000)
(2, ‘DEF’, 250, 1000)
(3, ‘GHI’, 300, 2000)

then the function should display

Product ID: 1
Product ID: 3
Total expensive products: 2

Section-E (15 Marks)

33. Fun Media Services Ltd is an event planning organization. It is planning to set up its India campus in Mumbai with its head office in Delhi. The Mumbai campus will have four blocks/buildings – ADMIN, DECORATORS, FOOD, and MEDIA.

You as a network expert need to suggest the best network-related solutions for them to resolve the issues/problems mentioned in points (i) to (v), keeping in mind the distances between various blocks/buildings and other given parameters.

Shortest distance between various buildings:

The number of computers at various buildings is as follows:

i) Suggest the most appropriate location of the server inside the MUMBAI campus (out of the 4 buildings).Justify your answer.

ii) Draw the cable layout to efficiently connect various buildings within the MUMBAI campus.

iii) Which hardware device will you suggest to connect all the computers within each building?

iv) Which of the following will you suggest to establish online face-to-face communication between the people in the Admin Office of the MUMBAI campus and the DELHI Head Office?

a. Cable TV

b. Email

c. Video Conferencing

d. Text Chat

v) What type of network (out of PAN, LAN, MAN, WAN) will be set up in each of the following cases?

a. The Mumbai campus gets connected with the Head Quarter in Delhi

b. The computers connected in the MUMBAI campus

Class 12 Computer Science Sample Paper 2024

34.

i)  Mention any two differences between seek() and tell().

ii)  Consider a file FLIGHT.DAT containing multiple records. The structure of each record is as shown below:

[Fno, FName, Fare, Source, Destination]

Write a function COPY_REC() in Python that copies all those records from FLIGHT.DAT where the source is DELHI and the destination is MUMBAI, into a new file RECORD.DAT

OR

i) Mention any two differences between binary files and csv files?

ii) Consider a Binary file BOOK.DAT containing a dictionary having multiple elements. Each element is in the form BNO

[BNAME,BTYPE,PRICE] as key:value pair where
BNO – Book Number
BNAME – Book Name
BTYPE – Book Type
PRICE – Book price

Write a user-defined function, findBook(price), that accepts price as parameter and displays all those records from the binary file BOOK.DAT which has a book price more than or equal to the price value passed as a parameter.

35.

i) Define the term constraint with respect to RDBMS. Give a suitable example.

ii) Sameera maintains a database named STORE which contains a table named ITEM with the structure given below:
• Ino(Item number )- integer
• Iname(Item Name) – string
• Price (Item Price) – float
• Discount (Discount) – float

Note the following to establish connectivity between Python and MySQL:
• Username – root
• Password – tiger
• Host – localhost

Help her to remove the record from the table ITEM for a particular value of item name input by the user.
import mysql.connector as mysql
con1= mysql.connect(host=’localhost’, user=’root’, password=
‘__’, database=’STORE’) #Statement-1
mycursor = ________ #Statement-2
item_name = input(“Enter the Item name to remove the record : “)
query = ______________ #Statement-3
mycursor.execute(query)
con1.____ #Statement-4
print(‘Data Deleted successfully’)
con1.close()

With reference to the above code, answer the following questions

a) Complete statement 1 to establish the connection with the database.

b) Write statement 2 to create the cursor object.

c) Complete statement 3 to remove the record from the table ITEM based on the item name entered by the user

d) Complete statement 4 to save the changes in the table.

OR

i) Write one difference between the alternate key and the candidate key.

ii)  A table named ITEM is created in a database STORE. The table contains multiple columns whose details are as shown below:

•Ino(Item number )- integer

• Iname(Item Name) – string

• Price (Item Price) – float

• Discount (Discount) – float

Note the following to establish connectivity between Python and MySQL:

•Username – root

•Password – tiger

•Host – localhost

However, the table is to be interfaced with Python to perform certain tasks. The incomplete code is given below:

______ #Line 1
con1= mysql.connect(host=’localhost’, user = ‘root’, password = ‘tiger’, database=’STORE’)
mycursor = con1.____ #Line 2
query = ‘SELECT * FROM ITEM where Price > {}’.format(___) #Line3
mycursor.execute(query)
data = mycursor.___ #Line 4
for rec in data:
print(rec)
con1.close()

i)  Complete line 1 to import the appropriate module.

ii) Complete Line 2 to create the cursor object

iii)  Complete the query given in Line 3 to display details of all such items from the table ITEMS whose price is more than 5000.

iv)  Complete Line 4 to extract all the records.

Class 12 Computer Science Sample Paper 2024

Class 12 Computer Science Sample Paper 2024