CBSE 12 Computer Science 2025: Most Expected Questions & Answers For Last Minute Revision

CBSE 12th exams are underway and your CBSE 12th Computer Science exam is scheduled for 29th March 2025. You have just a few hours left for the CBSE 12th Computer Science exam.

We know how important it is to focus on the right topics and questions during revision, so this article provides important CBSE 12th Computer Science Most Expected Questions with Solutions along with Answers for last minute revision.

👉 Read Also- CBSE 12 Computer Science Exam 2025: Fast-Track Revision Notes & Most Important Questions

Get most repeated questions for CBSE Class 12 CS. These questions are important and often appear in exams. Practice them well to prepare for the CBSE Class 12 Computer Science Exam 2025.

CBSE Board Class 12 CS Most Important Questions Answers

Q1: Given the following Tuple - Tup = (10, 20, 30, 50) Which of the following statements will result in an error? 

(a) print (Tup [0])

(b) Tup.insert 

(c) print (Tup [1:2])

(d) print (len (Tup))

Answer: Tup.insert 

Q2: Consider the given expression: 5<10 and 12>7 or not 7>4 Which of the following will be the correct output of the given expression evaluated? 

(a) True

(b) False

(c) NONE

(d) NULL

Answer: True

Q3: Fill in the blank: ___ is used for point-to-point communication or unicast communication such as radar and satellite. 

(a) Infrared waves

(b) Bluetooth

(c) Microwaves

(d) Radiowaves

Answer: Microwaves

👉 Read Also- CBSE  12 Computer Science Sample Paper 2024-25

Q4: Fill in the blank: ___ clause is used with a SELECT statement to display data in a sorted form with respect to a specified column.

(a) Where

(b) Order by

(c) Having 

(d) Distinct

Answer: (b) Order by

Q5: What will the following expression be evaluated to in Python? print (4+3*5/3-5%2) 

(a) 8.5

(b) 8.0

(c) 10.2

(d) 10.0

Answer: (b) 8.0

Q6: fetchall () method fetches all rows in a result set and returns a: 

(a) Tuple of lists

(b) List of Tuples

(c) List of strings

(d) Tuple of strings

Answer: (b) List of Tuples

Q7: Which function returns the sum of all elements of a list? 

(a) count ()

(b) sum ()

(c) total ()

(d) add ()

Answer: (b) sum ()

Q8: What error occurs when you execute the following Python code snippet? apple = mango

a) SyntaxError

b) NameError

c) ValueError

d) TypeError

Answer. b) NameError

Q9. Which point can be considered as difference between string and list?

a) Length

b) Mutability 

c) Indexing and Slicing

d) Accessing individual elements

Answer: B) Mutability

👉 Read Also- CBSE Class 12 Study Materials

CBSE Class 12 Syllabus 2024-25	CBSE Class 12 Previous Year Papers
NCERT Books For Class 12 Books	NCERT Class 12 Solutions
CBSE Class 12 Full Study Material	CBSE Class 12 Sample Paper 2024-25

Q10. To read the entire remaining contents of the file as a string from a file object myfile, we use

a) myfile.read(2)

b) myfile.read()

c) myfile.readline()

d) myfile.readlines()

Answer: b) myfile.read()

Important Subjective Questions for CBSE Class 12 Computer Science

Q1: What is polymorphism?

Answer: Polymorphism in computer science refers to the ability of a function, method, or operator to behave differently based on the inputs. In Object-Oriented Programming, it allows objects of different classes to be treated as objects of a common superclass.

Q2: Write a Python program to find the factorial of a number.

Answer:

def factorial_iterative(n):
    result = 1
    for i in range(1, n + 1):
        result *= i
    return result

# Example usage
number = 5
print(f"The factorial of {number} (iterative) is: {factorial_iterative(number)}")

Q3: Explain Data Abstraction with an example.

Answer: Data Abstraction refers to providing only essential information while hiding the details. For example, a car's dashboard shows speed and fuel level without showing the engine's complexities.

Q4: What are tokens in C++?

Answer: Tokens are the smallest units in a C++ program. These could be keywords, identifiers, literals, operators, and punctuation symbols.

Q5: Write the output of the code given below: 

def short_sub(lst, n): 
    for i in range(n): 
        if len(lst) > 4:
            lst[i] = lst[i] + lst[i]
        else: 
            lst[i] = lst[i]

subject = ['CS', 'HINDI', 'PHYSICS', 'CHEMISTRY', 'MATHS']
short_sub(subject, 5)
print(subject)

Answer: ['CSCS', 'HINDIHINDI', 'PHYSICSPHYSICS', 'CHEMISTRYCHEMISTRY', 'MATHSMATHS']

Q6: Differentiate between wired and wireless transmission. 

Answer:

Aspect	Wired Transmission	Wireless Transmission
Definition	Uses physical cables (e.g., twisted pair, coaxial, fiber optic) to transmit data	Uses electromagnetic waves (e.g., Wi-Fi, Bluetooth, cellular) to transmit data
Advantages	Stable connection	Greater mobility
	More secure	Easier installation
	Higher speeds	More convenient
Disadvantages	Limited mobility	Potential interference
	Difficult and costly to install	Less secure
	Requires maintenance	Generally slower speeds than wired

Q7: Differentiate between URL and domain name with the help of an appropriate example. 

Answer:

A URL (Uniform Resource Locator) is the full address used to access a specific resource on the internet, while a domain name is a part of the URL that represents the main address of a website.

Example:

URL: https://www.example.com/page1.html - This specifies the protocol (https), the domain name (example.com), and the specific page (/page1.html).

Domain Name: example.com - This is the main address of the website, which can host various pages and resources.

Q8: Given is a Python list declaration, what will be the output

Listofnames = ["Aman", "Ankit", "Ashish", "Rajan", "Rajat"]
print(Listofnames[-1:3:-1])

Answer: ['Rajat']

Q9: Consider the following tuple declaration: Write the output of: 

tupl = (10, 20, 30, (10, 20, 30), 40)
print(tupl.index(20))

Answer: 1

Q10: Differentiate between % (percentage) and _(underscore) characters used with the LIKE operator in SQL with appropriate examples.

Answer:

% (percentage): Matches zero, one, or more characters.

Example: WHERE name LIKE 'A%' finds all names starting with 'A'.

_ (underscore): Matches exactly one character.

Example: WHERE name LIKE '_orld' finds all five-letter names ending with 'orld'.