CBSE Sample Papers for Class 12 Computer Science Term 2 Set 1 with Solutions

Students can access the CBSE Sample Papers for Class 12 Computer Science with Solutions and marking scheme Term 2 Set 1 will help students in understanding the difficulty level of the exam.

CBSE Sample Papers for Class 12 Computer Science Term 2 Set 1 with Solutions

Time: 2 Hours
Maximum Marks: 35

General Instructions:

• The question paper is divided into 3 sections – A, B and C
• Section A, consists of 7 questions (1 – 7). Each question carries 2 marks.
• Section B, consists of 3 questions (8 – 10). Each question carries 3 marks.
• Section C, consists of 3 questions (11 – 13). Each question carries 4 marks.
• Internal choices have been given for question numbers 7, 8 and 12.

Section – A
(2 Marks Each)

Question 1.
Give any two characteristics of stacks.
Answer:
Characteristics of Stacks:

• The insertion and deletion happens at one end i.e. from the top of the stack
• Stack is a linear data structure based on LIFO (Last In First Out) order

Question 2.
(a) Expand the following:
SMTP , XML
Answer:

• SMTP: Simple Mail Transfer Protocol
• XML: Extensible Mark Up Language

(b) Out of the following, which is the fastest wired and wireless medium of transmission?
Infrared, coaxial cable, optical fibre, microwave, Ethernet cable
Answer:
Wired: Optical Fibre Wireless: Microwave

Question 3.
Differentiate between char(n) and varchar(n) data types with respect to databases.
Answer:
char(n):

•  Stores a fixed length string between 1 and 255 characters.
•   If the value is of smaller length, adds blank spaces.
•  Some space is wasted.

varchar(n):

• Stores a variable length string.
• No blanks are added even if value is of smaller length.
• No wastage of space.

Question 4.
A result set is extracted from the database using the cursor object (that has been already created) by giving the following statement.
My data = cursor. fetchone()
(a) How many records will be returned by fetchone() method?
Answer: One record

(b) What will be the datatype of Mydata object after the given command is executed?
Answer: Tuple

Question 5.
Write the output of the queries (a) to (d) based on the table, Furniture given below:

FID	NAME	DATE OF PURCHASE	COST	DISCOUNT
B001	Double Bed	03-Jan-2018	45000	10
T010	Dining Table	10-Mar-2020	51000	5
B004	Single Bed	19-Ju 1-2021	22000	0
C003	Long Back Chair	30-Dec-2016	12000	3
T006	Console Table	17-Nov-2019	15000	12
B006	Bunk Bed	01-Jan-2021	28000	14

(a) SELECT SUM (DISCOUNT)
FROM FURNITURE WHERE COST>15000;
Answer: 29

(b) SELECT MAX(DATEOFPURCHASE)
FROM FURNITURE;
Answer: 19 – July – 2021

(c) SELECT * FROM FURNITURE
WHERE DISCOUNTS AND FID LIKE “T%”;
Answer:

T006

Console Table

17-Nov-2019

15000

12

(d) SELECT DATEOFPURCHASE FROM FURNITURE
WHERE NAME IN (“Dining Table”, “Console Table”);
Answer:

• 10-Mar-2020
• 17-Nov-2019

Question 6.
a) Which command is used to view the list of tables in a database?
Answer:
SHOW TABLES;

(b) Give one point of difference between an equi-join and a natural join.
Answer:
Equi- join:

• The join in which columns from two tables are compared for equality.
• Duplicate columns are shown.

Natural Join:

• The join in which only one of the identical columns existing in both tables is present.
• No duplication of columns.

Question 7.
Consider the table, MOVIEDETAILS given below:
Table of MovieDetails

MOVIEID	TITLE	LANGUAGE	RATING	PLATFORM
M001	Minari	Korean	5	Netflix
M004	MGR Magan	Tamil	4	Hotstar
M010	Kaagaz	Hindi	3	Zee5
M011	Harry Potter and the Chamber of Secrets	English	4	Prime Video
M015	Uri	Hindi	5	Zee5
M020	Avengers: Endgame	English	4	Hotstar

(a) Identify the degree and cardinality of the table.
Answer:

• Degree: 5
• Cardinality: 6

(b) Which field should be made the primary key? Justify your answer.
Answer:
MOVIEID should be made the primary key as it uniquely identifies each record of the table.

OR

(a) Identify the candidate key(s) from the table MOVIEDETAILS.
Answer:
MOVIEID AND TITLE

(b) Consider the table SCHEDULE given below:
Table of Schedule

SLOTID	MOVIED	TIMESLOT
S001	M010	10 AM To 12PM
S002	M020	2PM To 5PM
S003	M010	6PM To 8PM
S004	M011	9PM To 11PM

Which field will be considered as the foreign key if the tables MOVIEDETAILS and SCHEDULE are related in a database.
Answer:
MOVIEID

Section – B
(3 Marks Each)

Question 8.
Julie has created a dictionary containing names and marks as key value pairs of 6 students. Write a program, with separate user defined functions to perform the following operations:

• Push the keys (name of the student) of the dictionary into a stack, where the corresponding value (marks) is greater than 75.
•  Pop and display the content of the stack.

For example:
If the sample content of the dictionary is as follows:
R ={“OM”:76, “JAI”:45, “BOB”:89, “ALI”:65, “ANU”:90,
The output from the program should be:
TOM ANU BOB OM

OR

Alam has a list containing 10 integers. You need to help him create a program with separate user defined functions to perform the following operations based on this list.

• Traverse the content of the list and push the even numbers into a stack.
• Pop and display the content of the stack.

For Example
If the sample Content of the list is as follows:
N=[12,13, 34,56,21, 79, 98,22, 35, 38]
Sample Output of the code should be:
38 22 98 56 34 12
Answer:
# Question No 8 (first option)
R={“OM”:7 6, “JAI”:45, “BOB”:89, “ALI”:65, “ANU”:90, “TOM”:82} def PUSH(S,N):
S.append(N) def POP(S): if S! = [] :
return S.popO else:
return None
ST=[]
for k in R:
if R[k]>=75:
PUSH(ST,k) while True: if ST!=[]:
print(POP(ST),end=” “) else:
break

OR

N = [12, 13, 34, 56, 21, 79, 98, 22, 35, 38] def PUSH(S,N):
S.append(N)
def POP (S) : .
if S!=[]:
return S.popO else:
return None
ST=[]
for k in N: if k%2==0:
PUSH(ST,k) while True:
if ST!=[]:
print (POP(ST),end=” “) else: break

Question 9.
(a) A table, ITEM has been created in a database with the following fields:
ITEMCODE, ITEMNAME, QTY, PRICE
Give the SQL command to add a new field, DISCOUNT (of type Integer) to the ITEM table.
Answer:
ALTER TABLE Item ADD (Discount INT);

(b) Categorize following commands into DDL and DML commands?
INSERT INTO, DROP TABLE, ALTER TABLE, UPDATE, SET
Answer:

• DDL: DROP TABLE, ALTER TABLE
• DML: INSERT INTO, UPDATE…SET

Question 10.
Charu has to create a database named MYEARTH in MYSQL.
She now needs to create a table named CITY in the database to store the records of various cities across the globe. The table CITY has the following structure:
Table: CITY

FIELD NAME	DATATYPE	REMARKS
CITY CODE	CHAR(5)	Primary Key
CITY NAME	CHAR(30)
SIZE	INTEGER
AVGTEMP	INTEGER
POLUTION RATE	INTEGER
POPULATION	INTEGER

Help her to complete the task by suggesting appropriate SQL commands.
Answer:
CREATE DATABASE MYEARTH;
CREATE TABLE CITY
(
CITYCODE CHAR(5)PRIMARY KEY,
CITYNAME CHAR(30),
SIZE INT,
AVGTEMP INT,
POPULATIONRATE INT,
POPULATION INT,
) ;

Section – C
(4 Marks Each)

Question 11.
Write queries (a) to (d) based on the tables EMPLOYEE and DEPARTMENT given below:
Table: EMPLOYEE

EMPID	NAME	DOB	DEPITED	DESIG	SALARY
120	Alisha	23-Jan-1978	D001	Manager	75000
123	Nitin	10-Oct-1977	D002	AO	59000
129	Navjot	12-Jul-1971	D003	Supervisor	40000
130	Jimmy	30-Dec-1980	D004	Sales Rep
131	Faiz	06-Apr-1984	D001	Dep Manager 65000

Table: DEPARTMENT

DEPITED	DEPTNAME	FLOOORNO
D001	Personal	4
D002	Admin	10
D003	Production	1
D004	Sales	3

(a) To display the average salary of all employees, department wise.
Answer:

• SELECT AVG (SALARY)
• FROM EMPLOYEE
• GROUP BY DEPTID;

(b) To display name and respective department name of each employee whose salary is more than 50000.
Answer:

• SELECT NAME, DEPTNAME FROM EMPLOYEE, DEPARTMENT WHERE
• EMPLOYEE.DEPTID=
• DEPARTMENT.DEPTID
• AND SALARY>50000;

(c) To display the names of employees whose salary is not known, in alphabetical order.
Answer:

• SELECT NAME FROM EMPLOYEE
• WHERE SALARY IS NULL
• ORDER BY NAME;

(d) To display DEPTID from the table EMPLOYEE without repetition.
Answer:
SELECT DISTINCT DEPTID FROM EMPLOYEE;

Question 12.
(a) Give two advantages and two disadvantages of star topology.
OR
Define the following terms: WWW, Web hosting
Answer:
Advantages

• Ease of service.
• Centralized control.
• Easy to diagnose faults.
• One device per connection.

Disadvantages

• Long cable length.
• Difficult to expand.
• Central node dependency.

OR

WWW: A set of protocols that allow you to access any document on the internet through the naming systems based on URLs.
Web hosting:
Web hosting is a service that allows organizations and individuals to post a website or web page onto the server, which can be viewed by everyone on the Internet.

(b) How is Packet Switching different from Circuit Switching?
Answer:
Packet switching:

• Uses store and forward concept to send messages.
• No physical path is actually establishes.
• Message is divided into smaller parts, known as packets and then sent forward.
• Tight upper limit on block size.
• Each data unit knows only the final receiver’s address.

Circuit switching:

• Physical connection is established between sender and receiver.
• Each data unit knows the entire path from sender to receiver.
•  It does not follow store and forward concept.

Question 13.
Be Happy Corporation has set up its new centre at Noida, Uttar Pradesh for its office and web-based activities. It has 4 blocks of buildings.

Distance between the various blocks is as follows:
A to B    40 m
B to C     120 m
C to D     100m
A to D     170m
B to D     150m
A to C     70m
Numbers of computers in each block
Block A    25
Block B    50
Block C    125
Block D    10
(a) Suggest and draw the cable layout to efficiently connect various blocks of buildings within the Noida centre for connecting the digital devices.
Answer:

(b) Suggest the placement of the following device with justification:
(i) Repeater
(ii) Hub/Switch
Answer:

• Repeater: between C and D as the distance between them is 100 mts.
• Hub/ Switch: In each block as they help to share data packets within the devices of the network in each block.

(c) Which kind of network (PAN/LAN/WAN) will be formed if the Noida office is connected to its head office in Mumbai?
Answer:
WAN

(d) Which fast and very effective wireless transmission medium should preferably be used to connect the head office at Mumbai with the centre at Noida?
Satellite