2019 CBSE Class 12 Computer Science Question Paper with Detailed Solutions

This is the Class 12 CBSE Final Term Computer Science Question Bank. The students’ challenges are met through a set of questions and answers that cut across all topics. The questions are divided into sections including multiple choice, very short answer, short answer and long answer questions so as to enhance the revision. Detailed answers are interspersed in any patient section that can be disclosed. Use this question bank for revising the concepts, practicing important questions or preparing for the final examination.

Note: These questions are based on the latest syllabus updates and include previous year questions for reference. Ensure to review the solved examples provided to grasp complex topics with ease.

1. Question: Write the names of any four data types available in Python.
   
   SHOW ANSWER

   Answer:

   • Integer
   • Float
   • String
   • Boolean
2. Question: Name the Python Library modules which need to be imported to invoke the following functions:
   • (i) sqrt()
   • (ii) start() (This might refer to another function)
   SHOW ANSWER

   Answer:

   • import math for sqrt()
   • Note: There is no start() function in the standard library. It may refer to another function.
3. Question: Rewrite the following code in Python after removing all syntax errors:

   
   250 = Number
   WHILE Number <= 1000: if Number => 750:
           print Number
           Number = Number + 100
       else:
           print Number * 2
           Number = Number + 50
           

   SHOW ANSWER

   Corrected code:

   
   Number = 250
   while Number <= 1000: if Number >= 750:
           print(Number)
           Number += 100
       else:
           print(Number * 2)
           Number += 50
           

4. Question: Find and write the output of the following Python code:

   
   Msg1 = "WeLcOME"
   Msg2 = "GUeSTs"
   Msg3 = ""
   for I in range(0, len(Msg2) + 1):
       if Msg1[I] >= "A" and Msg1[I] <= "M": Msg3 = Msg3 + Msg1[I] elif Msg1[I] >= "N" and Msg1[I] <= "Z":
           Msg3 = Msg3 + Msg2[I]
       else:
           Msg3 = Msg3 + "*"
   print(Msg3)
           

   SHOW ANSWER

   Output:

   WeL**ME*

5. Question: Write four features of object-oriented programming.
   
   SHOW ANSWER

   • Encapsulation
   • Inheritance
   • Polymorphism
   • Abstraction
6. Question: Write the output of the following Python code:

   
   class Box:
       L = 10
       Type = "HARD"
       
       def __init__(self, T, TL=30):
           self.Type = T
           self.L = TL
           
       def Disp(self):
           print(self.Type, Box.Type)
           print(self.L, Box.L)
   
   B1 = Box("SOFT", 20)
   B1.Disp()
   
   Box.Type = "FLEXI"
   B2 = Box("HARD")
   B2.Disp()
           

   SHOW ANSWER

   Output:

   SOFT HARD
   20 10
   HARD FLEXI
   30 10
   

7. OR: Write the output of the following Python code:

   
   class Target:
       def __init__(self):
           self.X = 20
           self.Y = 24
           
       def Disp(self):
           print(self.X, self.Y)
           
       def __del__(self):
           print("Target Moved")
           
   def One():
       T = Target()
       T.Disp()
       
   One()
           

   SHOW ANSWER

   Output:

   20 24
   Target Moved
   

8. Question: Define a class HOUSE in Python with the following specifications:
   • Instance Attributes: Hno, Nor, Type
   • Methods/Functions:
     • AssignType(): Assigns house type based on Nor
     • Enter(): Allows user input for Hno and Nor
     • Display(): Displays the house details
   SHOW ANSWER

   
   class HOUSE:
       def __init__(self):
           self.Hno = None
           self.Nor = None
           self.Type = None
   
       def AssignType(self):
           if self.Nor <= 2:
               self.Type = "LIG"
           elif self.Nor == 3:
               self.Type = "MIG"
           else:
               self.Type = "HIG"
   
       def Enter(self):
           self.Hno = int(input("Enter House Number: "))
           self.Nor = int(input("Enter Number of Rooms: "))
           self.AssignType()
   
       def Display(self):
           print(f"House No: {self.Hno}, Rooms: {self.Nor}, Type: {self.Type}")
           

9. Question: Show the first, second, and third pass of selection sort for the list:

   106, 104, 106, 102, 105, 10

   SHOW ANSWER

   Answer:

   • 1st Pass: [10, 104, 106, 102, 105, 106]
   • 2nd Pass: [10, 102, 106, 104, 105, 106]
   • 3rd Pass: [10, 102, 104, 106, 105, 106]
10. OR: Show the first, second, and third pass of bubble sort for the list:

    106, 104, 106, 102, 105, 107

    SHOW ANSWER

    Answer:

    • 1st Pass: [106, 106, 104, 105, 102, 107]
    • 2nd Pass: [106, 106, 105, 104, 102, 107]
    • 3rd Pass: [106, 106, 105, 104, 107, 102]
11. Question: Write a Python function to count how many times the value Val is present in the list ID.

    
    ID = [115, 122, 137, 110, 122, 113]
    Val = 122
            

    SHOW ANSWER

    Answer:

    
    def HowMany(ID, Val):
        count = ID.count(Val)
        print(f"{Val} found {count} times")
    
    ID = [115, 122, 137, 110, 122, 113]
    Val = 122
    HowMany(ID, Val)
            

12. OR: Write Python methods for queue operations QueueUp() to add a client and QueueDel() to delete a client.
    
    SHOW ANSWER

    
    def QueueUp(queue, client):
        queue.append(client)
    
    def QueueDel(queue):
        if queue:
            return queue.pop(0)
        else:
            return "Queue is empty"
    
    queue = []
    QueueUp(queue, "Client1")
    QueueUp(queue, "Client2")
    QueueDel(queue)
            

13. Question: Write the SQL queries to:
    • (i) Display details of all Trains which Start from New Delhi.
    • (ii) Display the PNR, PNAME, GENDER, and AGE of all Passengers whose AGE is below 50.
    SHOW ANSWER

    Answers:

    (i) SELECT * FROM TRAINS WHERE START = 'New Delhi';

    (ii) SELECT PNR, PNAME, GENDER, AGE FROM PASSENGERS WHERE AGE < 50;

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