2018 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 reshow the solved examples provided to grasp complex topics with ease.

Section B – Python Programming

1. (a) Differentiate between Syntax Error and Run-Time Error. Also, write a suitable example in Python to illustrate both.

print "Hello World"  # Missing parentheses

a = 10
b = 0
print(a / b)  # Division by zero

1. (b) Name the Python Library modules which need to be imported to invoke the following functions:

1. 1. sin()

1. 1. search()

1. (c) Rewrite the following code in Python after removing all syntax errors.

Val = int(input("Value:"))  
Adder = 0  
for C in range(1, Val, 3):  
    Adder += C  
    if C % 2 == 0:  
        print(C * 10)  
    else:  
        print(C * 1)
print(Adder)

1. (d) Find and write the output of the following Python code:

Data = ["P", 20, "R", 10, "S", 30]
Times = 0
Alpha = ""
Add = 0
for C in range(1, 6, 2):
    Times = Times + C
    Alpha = Alpha + Data[C-1] + "$"
    Add = Add + Data[C]
print(Times, Add, Alpha)

1. (e) Find and write the output of the following Python code:

class GRAPH:
    def __init__(self, A=50, B=100):
        self.P1 = A
        self.P2 = B
    def Up(self, B):
        self.P2 = self.P2 - B
    def Down(self, B):
        self.P2 = self.P2 + 2 * B
    def Left(self, A):
        self.P1 = self.P1 - A
    def Right(self, A):
        self.P1 = self.P1 + 2 * A
    def Target(self):
        print("(", self.P1, ":", self.P2, ")")

G1 = GRAPH(200, 150)
G2 = GRAPH()
G3 = GRAPH(100)
G1.Left(10)
G2.Up(25)
G3.Down(75)
G1.Up(30)
G3.Right(15)
G1.Target()
G2.Target()
G3.Target()

(190 : 120)
(50 : 75)
(130 : 250)

1. (f) What possible output(s) are expected to be displayed on screen at the time of execution of the program from the following code?

import random
POINTS = [30, 50, 20, 40, 45]
BEGIN = random.randint(1, 3)
LAST = random.randint(2, 4)
for C in range(BEGIN, LAST + 1):
    print(POINTS[C], "#", end=" ")

2. (a) What is the advantage of super() function in inheritance? Illustrate the same with the help of an example in Python.

class Parent:
    def display(self):
        print("Parent class")

class Child(Parent):
    def display(self):
        super().display()
        print("Child class")

C = Child()
C.display()

2. (b) Consider the following Python code and answer the questions below:

class Vehicle:
    Type = 'Car'
    def __init__(self, name):
        self.Name = name
    def Show(self):
        print(self.Name, Vehicle.Type)

V1 = Vehicle("BMW")
V1.Show()
Vehicle.Type = "Bus"
V2 = Vehicle("VOLVO")
V2.Show()

BMW Car
VOLVO Bus

2. (c) Define a class CONTAINER in Python with the following specifications:

class CONTAINER:
    def __init__(self):
        self.Radius = 0
        self.Height = 0
        self.Type = 0
        self.Volume = 0
    
    def CalVolume(self):
        if self.Type == 1:
            self.Volume = 3.14 * self.Radius * self.Height
        elif self.Type == 3:
            self.Volume = 3.14 * self.Radius * self.Height / 3
    
    def GetValue(self):
        self.Radius = float(input("Enter Radius: "))
        self.Height = float(input("Enter Height: "))
        self.Type = int(input("Enter Type (1 or 3): "))
        self.CalVolume()
    
    def ShowContainer(self):
        print("Radius:", self.Radius)
        print("Height:", self.Height)
        print("Type:", self.Type)
        print("Volume:", self.Volume)

C = CONTAINER()
C.GetValue()
C.ShowContainer()

2. (d) Answer the questions (i) to (iv) based on the following code:

class Top1(object):
    def __init__(self, tx):
        self.X = tx
    def ChangeX(self, tx):
        self.X = self.X + tx
    def ShowX(self):
        print(self.X)

class Top2(object):
    def __init__(self, ty):
        self.Y = ty
    def ChangeY(self, ty):
        self.Y = self.Y + ty
    def ShowY(self):
        print(self.Y, end=" ")

class Bottom(Top1, Top2):
    def __init__(self, tz):
        self.Z = tz
        Top2.__init__(self, 2 * tz)
        Top1.__init__(self, 3 * tz)
    def ChangeZ(self, tz):
        self.Z = self.Z + tz
        self.ChangeY(2 * tz)
        self.ChangeX(3 * tz)
    def ShowZ(self):
        print(self.Z, end=" ")
        self.ShowY()
        self.ShowX()

B = Bottom(1)
B.ChangeZ(2)
B.ShowZ()

3 6 9

3. (a) Consider the following randomly ordered numbers stored in a list: 786, 234, 526, 132, 345, 467. Show the content of the list after the First, Second, and Third pass of the bubble sort method used for arranging in ascending order.

3. (b) Write the definition of a method ZeroEnding(SCORES) to add all those values in the list of SCORES, which are ending with zero (0) and display the sum.

def ZeroEnding(SCORES):
    total = 0
    for score in SCORES:
        if score % 10 == 0:
            total += score
    print("Sum of values ending with 0:", total)

# Example usage:
ZeroEnding([200, 456, 300, 100, 234, 678])

3. (c) Write AddClient(Client) and DeleteClient(Client) methods in Python to add a new Client and delete a Client from a List of Client Names, considering them to act as insert and delete operations of the queue data structure.

class ClientQueue:
    def __init__(self):
        self.clients = []
    
    def AddClient(self, client):
        self.clients.append(client)
    
    def DeleteClient(self):
        if self.clients:
            return self.clients.pop(0)  # Dequeue
        else:
            return "Queue is empty"

# Example usage:
queue = ClientQueue()
queue.AddClient("Client1")
queue.AddClient("Client2")
queue.DeleteClient()

3. (d) Write a definition of a method COUNTNOW(PLACES) to find and display those place names, in which there are more than 5 characters.

def COUNTNOW(PLACES):
    for place in PLACES:
        if len(place) > 5:
            print(place)

# Example usage:
COUNTNOW(["DELHI", "LONDON", "PARIS", "NEW YORK", "DUBAI"])

3. (e) Evaluate the following Postfix notation of expression: 22, 11, /, 5, 10, *, +, 12, -

        22 / 11 = 2
        5 * 10 = 50
        2 + 50 = 52
        52 - 12 = 40

4. (a) Write a statement in Python to open a text file STORY.TXT so that new contents can be added at the end of it.

file = open("STORY.TXT", "a")  # 'a' mode to append

4. (b) Write a method in Python to read lines from a text file INDIA.TXT, to find and display the occurrence of the word “India.”

def CountIndia():
    count = 0
    with open("INDIA.TXT", "r") as file:
        for line in file:
            count += line.lower().count("india")
    print("The word 'India' appeared", count, "times")

# Example usage:
CountIndia()

4. (c) Considering the following definition of class MULTIPLEX, write a method in Python to search and display all the contents in a pickled file CINEMA.DAT, where MTYPE is matching with the value ‘Comedy’.

class MULTIPLEX:
    def __init__(self, mno, mname, mtype):
        self.MNO = mno
        self.MNAME = mname
        self.MTYPE = mtype
    def Show(self):
        print(self.MNO, "*", self.MNAME, "$", self.MTYPE)

import pickle

def SearchComedy():
    with open("CINEMA.DAT", "rb") as file:
        try:
            while True:
                multiplex = pickle.load(file)
                if multiplex.MTYPE == "Comedy":
                    multiplex.Show()
        except EOFError:
            pass

# Example: 
# SearchComedy() will display all records where MTYPE is "Comedy".

Section C – Database and Boolean Algebra

5. (a) Observe the following tables VIDEO and MEMBER carefully and write the name of the RDBMS operation out of SELECTION, PROJECTION, UNION, CARTESIAN PRODUCT, which has been used to produce the output. Also, find the Degree and Cardinality of the final result.

5. (b) Write SQL queries for (i) to (iv) and find outputs for SQL queries (v) to (viii) based on the following tables:

Table: ACCOUNT

Table: TRANSACT

SELECT * FROM TRANSACT WHERE TYPE = 'Deposit';

SELECT ANO, AMOUNT FROM TRANSACT WHERE DOT BETWEEN '2017-10-01' AND '2017-10-31';

SELECT MAX(DOT) FROM TRANSACT WHERE ANO = 103;

SELECT ACCOUNT.ANO, ANAME, DOT FROM ACCOUNT JOIN TRANSACT ON ACCOUNT.ANO = TRANSACT.ANO WHERE AMOUNT <= 3000;

6. (a) State any one Absorption Law of Boolean Algebra and verify it using a truth table.

| A | B | A.B | A + (A.B) |
|---|---|-----|-----------|
| 0 | 0 |  0  |     0     |
| 0 | 1 |  0  |     0     |
| 1 | 0 |  0  |     1     |
| 1 | 1 |  1  |     1     |

6. (b) Draw the Logic Circuit of the following Boolean Expression: (U’ + V).(V’ + W’)

6. (c) Derive a Canonical POS expression for a Boolean function FN, represented by the following truth table:

| X | Y | Z | FN(X, Y, Z) |
|---|---|---|-------------|
| 0 | 0 | 0 | 1           |
| 0 | 0 | 1 | 1           |
| 0 | 1 | 0 | 0           |
| 0 | 1 | 1 | 0           |
| 1 | 0 | 0 | 1           |
| 1 | 0 | 1 | 0           |
| 1 | 1 | 0 | 0           |
| 1 | 1 | 1 | 1           |

(X + Y' + Z')(X + Y' + Z)(X' + Y + Z)(X' + Y + Z')

6. (d) Reduce the following Boolean Expression to its simplest form using K-Map: G(U, V, W, Z) = Σ(3, 5, 6, 7, 11, 12, 13, 15)

G(U, V, W, Z) = U'W + VZ'

7. (a) Differentiate between Bus Topology and Star Topology of Networks. What are the advantages and disadvantages of Star Topology over Bus Topology?

7. (b) Classify each of the following Web Scripting languages as Client-Side Scripting or Server-Side Scripting:

1. 1. JavaScript

1. 1. ASP

1. 1. VBScript

1. 1. JSP

7. (c) Write the expanded names for the following abbreviated terms used in Networking and Communications:

1. 1. SMTP

1. 1. VoIP

1. 1. GSM

1. 1. WLL

7. (d) Case Study Based Question:
Ayurveda Training Educational Institute is setting up its center in Hyderabad with four specialized departments for Orthopedics, Neurology, Pediatrics, and an Administrative Office in separate buildings. The physical distances between these department buildings and the number of computers to be installed in these departments and administrative office are given below. You, as a network expert, have to answer the queries as raised by them in (i) to (iv).

Shortest distances between various locations in meters:

Number of Computers installed at various locations:

As a network expert, answer the following:

(i)

1. 1. Suggest the most suitable location to install the main server of this institution to get efficient connectivity.

(ii)

1. 1. Suggest the best cable layout for effective network connectivity of the building having the server with all the other buildings.

(iii)

1. 1. Suggest the devices to be installed in each of these buildings for connecting computers installed within the building out of the following: Gateway, Modem, Switch.

(iv)

1. 1. Suggest the topology of the network and network cable for efficiently connecting each computer installed in each of the buildings out of the following:

(a)

1. 1. 1. Topologies: Bus Topology, Star Topology

(b)

1. 1. 1. Network Cable: Single Pair Telephone Cable, Coaxial Cable, Ethernet Cable