MBOSE Class 12 Question Paper 2020 for Computer Science

Total No. of Printed Pages—8
HS/XII/A.Sc.Com/CSc/NC/20

2020

COMPUTER SCIENCE

( New Course )

Full Marks : 70

Time : 3 hours

The figures in the margin indicate full marks for the questions

General Instructions :

(i) Write all the answers in the Answer Script.

(ii) Attempt multiple choice questions and very short
answer-type questions serially.

(iii) Attempt all parts of a question together at one place.

1. Choose the correct option for the following :
1×6=6
(a) Which of the following keywords marks the
beginning of a function block in Python?

(i) func

(ii) define

(iii) def

(iv) function

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( 2 )

(b) Which one of the following statements returns an
error while importing ‘Pyplot’ interface of ‘Matplotlib’
library?
(i) import matplotlib.pyplot
(ii) import matplotlib.pyplot as plt
(iii) from matplotlib import pyplot as plt
(iv) from matplotlib.pyplot as plt

(c) Assume that 30 employees are working in a Bank.
Each employee has been allotted a separate
workstation to work and all these workstations are
connected through the server. These workstations
are distributed over two floors of the same building.
In each floor, workstations are connected to a
switch. Identify the type of network used in the
Bank.
(i) Personal Area Network (PAN)
(ii) Local Area Network (LAN)
(iii) Wide Area Network (WAN)
(iv) Peer-to-Peer (P2P) Network

(d) _____ is a unique address consisting of numbers
separated by dots and is used for identifying a
device on the TCP/IP protocol.
(i) Web address
(ii) DNS
(iii) IP address
(iv) MAC address

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(e) Which SQL statement allows you to find the highest
‘price’ (column) from the table ‘Book’?
(i) SELECT Maximum(price) FROM Book;
(ii) SELECT MAX(price) FROM Book;
(iii) SELECT COUNT(price) FROM Book;
(iv) Both (i) and (ii)

(f) Excessive use of Internet affects the mental health of
a person, such condition is termed as ______ by
doctors.
(i) cybercrime
(ii) identity theft
(iii) Internet addiction
(iv) online stealing

2. Answer the following questions in not more than 2 (two)
or 3 (three) sentences : 1×5=5

(a) Write the most appropriate list method to add an
element in the beginning of the list.

(b) Mention any two advantages of computer network.

(c) What measures do wireless networks employ to
avoid collisions?

(d) Name any two types of cables that can be used in a
wired network.

(e) What is the use of ORDER BY clause in SQL
SELECT statement?

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( 4 )

3. Answer the following questions : 2×5=10

(a) What are base case and recursive case in a recursive
program?

(b) From the program code given below, identify
function header, function call, actual argument and
formal parameter :

def area(r) :
ar = 3.14 * r * r
return ar
#_main_
x=2
result = area(x)
Or
Predict the output of the following recursive code :

def func1 (a):
if a==1 :
return 1
else:
return a*a+func1(a – 1)
#_main_
n = 5
y = func1(n)
print (y)
(c) What are data structures? Name two common data
structures.
(d) How can you generate random number using
random( ) and randint( ) methods of random
module?
(e) Define Big-O notation.

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4. Answer the following questions in brief : 2×3=6

(a) Differentiate between Hub and Switch.

(b) What are the steps followed in checksum generator?

(c) What are the symptoms of network congestion?

5. Answer the following questions : 2×3=6

(a) Explain about HTTP GET request and POST
request in a web client-server architecture.

Or

How can you activate virtual environment for
Django project?

(b) Satyam Joshi is using a table ‘Employee’. It has
the following columns (fields) :
emp_code, emp_name, emp_salary and dept_code
He wants to display number of employees from
each department. He wrote the following
command :
SELECT dept_code COUNT(emp_code) FROM
Employee;
But he did not get the desired result. Rewrite the
above query with necessary changes to help him get
the desired output.
(c) What is the difference between a WHERE clause and
a HAVING clause of SQL SELECT statement?

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6. Answer the following questions : 3×3=9
(a) How can you open a data file in write mode,
read mode and append mode? Explain with
examples.
(b) Convert the infix expression (A+B) × C/D into postfix
notation.
Or
Write a linear search algorithm to search an element
in a linear list (array).
(c) What is a line graph? Which function is used for
drawing a line graph in Python using Pyplot
interface of Matplotlib library? How can you add title
and axes names for line graph?

7. Suppose you have created a Django project namely
‘School’. It contains three apps in it :
(a) Admission
(b) Exam
(c) Fees

What will be the structure of Django project folder?
Only list the folder, do not list any file inside app
folder. 3
Or
What is the use of ORDER BY clause? Write a query
that sorts the data of table ‘Student’ on the
basis of Project-Group (in ascending order); Section
(in descending order), Marks (in descending order).

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8. Answer the following questions : 3×3=9
(a) What are online scams? What measures will you
take to avoid online scams?
(b) What role has new age media played in things like
online campaigns, crowdsourcing and smart mobs?

Or

What is computer forensics? What important
practices are followed in computer forensics?
(c) How can you protect yourself against identity theft?

9. Answer the following questions : 4×2=8
a) What are the three types of formal arguments/
parameters that are supported by Python? Explain
each in brief.
(b) Write a program to create a data file which accepts
rollno, name and percentage of marks for ‘N’ number
of students from a user and display all the entered
records.

Or

Write a program using recursive function to
implement binary seach algorithm.

10. Explain about two main types of modulation. 4

Or

Explain the role of TCP and IP protocol on a network.

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11. Write a Python code to connect to a MySQL database
namely ‘Bank’ and then fetch all those records from the
table ‘Employee’ where salary > 40,000. 4

Or

Given the following table :
Table : CLUB

Give the output of following SQL statements :
(a) SELECT COUNT (DISTINCT SPORTS) FROM CLUB;
(b) SELECT MIN(Age) FROM CLUB WHERE Sex=‘F’;
(c) SELECT AVG(Pay) FROM CLUB WHERE
SPORTS= ‘Karate’;
(d) SELECT SUM(Pay) FROM CLUB WHERE DateofApp
> ‘31/01/1998’;

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HS/XII/A.Sc.Com/CSc/NC/20/34 20K—2280