Computer Science Sample Paper Term 2 Class 12

Sample Question Paper

COMPUTER SCIENCE (Code: 083)

Maximum Marks: 35 /Time: 2 hours

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

Each question carries 2 marks

1. Give any two characteristics of stacks.

Ans: Characteristics of Stacks:

> It is a LIFO data structure

> The insertion and deletion happens at one end i.e. from the top of the stack

2. (i) Expand the following: SMTP , XML

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

(ii) Out of the following, which is the fastest wired and wireless medium of transmission?

Infrared, coaxial cable, optical fibre, microwave, Ethernet cable

Ans: Wired- optical fibre
Wireless – microwave

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

Ans:

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

4. A resultset is extracted from the database using the cursor object (that has been already created) by giving the following statement.

Mydata=cursor.fetchone()

(a) How many records will be returned by fetchone() method?

Ans: One record

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

Ans: tuple

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

Table: FURNITURE

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

Ans: 29

(b) SELECT MAX(DATEOFPURCHASE) FROM FURNITURE;

Ans: 19-Jul-2021

(c) SELECT * FROM FURNITURE WHERE DISCOUNT>5 AND FID LIKE “T%”;

Ans:

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

Ans: 

10-Mar- 2020
17-Nov-2019

6. (i) Which command is used to view the list of tables in a database?

Ans: SHOW TABLES;

(ii) Give one point of difference between an equi-join and a natural join.

Ans:

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

7. Consider the table, MOVIEDETAILS given below:

Table: MOVIEDETAILS

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

Ans: Degree: 5, Cardinality: 6

(b) Which field should be made the primary key? Justify your answer.

Ans: 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.

Ans: MOVIEID and TITLE

(b) Consider the table SCHEDULE given below:

Table: SCHEDULE

Which field will be considered as the foreign key if the tables MOVIEDETAILS and SCHEDULE are related in a database?

Ans: MOVIEID

SECTION – B

Each question carries 3 marks

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, “TOM”:82}

The output from the program should be:

TOM ANU BOB OM

Ans: 

R={“OM”:76, “JAI”:45, “BOB”:89,
“ALI”:65, “ANU”:90, “TOM”:82}
def PUSH(S,N):
S.append(N)
def POP(S):
if S!=[]:
return S.pop()
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

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

Ans:

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.pop()
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

9. (i) 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.

Ans: ALTER TABLE Item
ADD (Discount INT);

(ii) Categorize following commands into DDL and DML commands?

INSERT INTO, DROP TABLE, ALTER TABLE, UPDATE…SET

Ans: 

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

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

Help her to complete the task by suggesting appropriate SQL commands.

CREATE DATABASE MYEARTH;
CREATE TABLE CITY (CITYCODE CHAR(5)PRIMARY KEY,
CITYNAME CHAR(30),
SIZE INT,
AVGTEMP INT,
POPULATIONRATE INT,
POPULATION INT,);

Section C

Each question carries 4 marks

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

Table: EMPLOYEE

Table: DEPARTMENT

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

Ans: 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.

Ans:

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.

Ans:SELECT NAME FROM EMPLOYEE
WHERE SALARY IS NULL
ORDER BY NAME;

(d) To display DEPTID from the table EMPLOYEE without repetition.

Ans:

SELECT DISTINCT DEPTID
FROM EMPLOYEE;

12. (i) Give two advantages and two disadvantages of star topology

Ans:

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

Define the following terms:

www , web hosting

Ans: 

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.

(ii) How is packet switching different from circuit switching?

Ans:

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

13. BeHappy 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 120m

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.

Ans: Block B>Block A>Block C>Block D

(b) Suggest the placement of the following device with justification

1. Repeater
2. Hub/Switch

Ans: 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?

Ans: 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?

Ans: Satellite

Also Check:

Computer Science Sample Paper Class 12 Term 2 Set 1

Computer Science Sample Paper Class 12 Term 2 Set 2

Computer Science Sample Paper Class 12 Term 2 Set 3

Computer Science Sample Paper Class 12 Term 2 Set 4

Computer Science Sample Paper Class 12 Term 2 Set 5

Computer Science Sample Paper Class 12 Term 2 set 6

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