SOLVED Pathibhara English School, Itahari, Sunsari First Term Question 2082 Subject: Computer Science

 

 

Pathibhara English School, Itahari, Sunsari

First Term Question 2082

Subject: Computer Science

 

Group-A [10 Marks]

1. Answer the following questions in one sentence. [6×1=6]

a. What term describes the unique address given to each device in a network?

IP address is the term used to describe the unique address given to each device in a network.

b. Give any two examples of bounded media for data transmission.

Two examples of bounded media are twisted pair cable and coaxial cable.

c. List any two components of data communication.

Two components of data communication are the sender and the transmission medium.

d. Which datatype is suitable for storing graphic content in MS-Access?    

  The suitable datatype for storing graphic content in MS-Access is OLE Object.

   

e. What is a tuple in database?

A tuple in a database is a single row or record in a table.

f. Define global variable in modular programming.

A global variable in modular programming is a variable that is declared outside all functions and is accessible throughout the program.

 

2. Write the appropriate technical terms for the following. [2×1=2]
   a. The security barrier that monitors and filters incoming and outgoing

    network traffic. Firewall
b. The set of rules that govern how data is sent and received over

                  the internet. Protocol

3. Write the full forms. [2×1=2]
   i. UTP - Unshielded Twisted Pair
   ii. NOS - Network Operating System

 

 

 

 

Group-B [24 Marks]

4.     Answer the following questions. [9×2=18]
a. Write any one difference between LAN and MAN. Draw well-labelled diagram  of star topology.

Any one difference between LAN and MAN is

LAN (Local Area Network) covers a small geographical area like a home, office, or building, whereas MAN (Metropolitan Area Network) spans a larger area, like a city or campus.

Diagram  of star topology:

                  [Computer]

                       |

[Computer] --- [Hub/Switch] --- [Computer]

                       |

                  [Computer]

b. What is ISP? Why internet is called network of network?
ISP (Internet Service Provider) is a company that provides users access to the Internet.

The Internet is called a network of networks because it connects millions of smaller networks globally, allowing them to communicate and share data.

 

c. What is malware? Mention two safety measures you can take to avoid malware on your computer or smartphone.

Malware is a malicious software designed to harm, exploit, or disable computers and networks.

Two safety measures you can take to avoid malware on your computer or smartphone are:

·  Install and regularly update antivirus software.

·  Avoid downloading files or clicking links from unknown or untrusted sources.

 

 

d. Define hardware security. List any two ways to protect hardware devices at home.

Hardware Security refers to the protection of physical devices from theft, damage, or unauthorized access.

Any two ways to protect hardware devices at home are:

·  Use surge protectors to prevent damage from power spikes.

·  Lock your devices or store them in secure places when not in use.

e. What is authentication? List some examples of biometric verifications.
The process of identifying an individual usually based on a username and password is called an authentication system.

Some examples of biometric verifications are:

·  Fingerprint recognition

·  Facial recognition

f. Explain about cryptography with a diagram.

Cryptography is the technique of securing data by converting it into a coded format to prevent unauthorized access.

Diagram

Plain Text → [Encryption] → Cipher Text → [Decryption] → Plain Text

          (Sender)                           (Receiver)

g.  You received an email claiming to be from your bank, asking for your account password. What type of cyberattack is this? What steps should you take in response?

The email is an example of a phishing attack, which attempts to trick users into providing sensitive information.

The steps should be taken are:

·  Do not reply or click on any links.

·  Report the email to your bank and delete it.

 

h. Write down the advantages of database management system (DBMS) over traditional data storage system.

The advantages of database management system (DBMS) over traditional data storage system

a)      It reduces data redundancy which means duplication of data.

b)     It allows multiple users to access the same data simultaneously.

c)      Large volume of data can be stored and updated easily.

d)     It provides high security of data as well as maintains accurate database.

 

i. Define Query and Report in MS Access.

A Query in MS Access is a request to retrieve specific data from one or more tables based on given criteria.

A Report is a formatted output that presents data from tables or queries, typically for printing or sharing.

 

 

5.     Write the output of the following program by making dry run table. [2]

DECLARE SUB series ( )

CALL series

END

SUB series ( )

i = 3

FOR c = 1 TO 5

t = i * (c ^ 2)

PRINT t;

NEXT c

END SUB

 

Dry Run

i	c = 1 TO 5	t = i * (c ^ 2)	PRINT t;
3	1 TO 5 Yes	3x(1^2)=3	3
	2 TO 5 Yes	3x(2^2)=12	12
	3 TO 5 Yes	3x(3^2)=27	27
	4 TO 5 Yes	3x(4^2)=48	48
	5 TO 5 Yes	3x(5^2)=75	75
	6 TO 5 No

The output of the program is:

3 12 27 48 75

 

6.     Re-write the given program after correcting the bugs. [2]

REM to find the factorial of a given number

DECLARE FUNCTION FACTO (N$)

CLS

INPUT "Enter a number"; N

CALL FACTO (N)

END

FUNCTION FACTO ()

F = 1

WHILE N = 0

F = F * N

N = N - 1

WEND

FACTO = F

END FUNCTION

 

Debugged Program

REM to find the factorial of a given number

DECLARE FUNCTION FACTO (N)

CLS

INPUT "Enter a number"; N

PRINT FACTO (N)

END

 

FUNCTION FACTO (N)

F = 1

WHILE N < > 0

F = F * N

N = N - 1

WEND

FACTO = F

END FUNCTION

 

7.     Study the given program and answer the given questions. [2]

DECLARE SUB SUM (N)

CLS

INPUT "Enter any number"; N

CALL SUM (N)

END

SUB SUM (N)

WHILE N > 0

R = N MOD 10

T = T + R

N = N \ 10

WEND

PRINT "The Sum of individual digit is"; T

END SUB

Questions:
a) How many parameter(s) is used in the above program? List them.

One parameter is used in the program.

b) Write the use of MOD in above program.

The MOD operator is used to find the remainder.

 

Group-C [16 Marks]

8.     Convert/Calculate the following as per instructions [4×1=4]
i. into Octal

 

986 ÷ 8 = 123, remainder 2 

123 ÷ 8 = 15, remainder 3 

15 ÷ 8 = 1, remainder 7 

1 ÷ 8 = 0, remainder 1

(986)₁₀ = (1732)₈

ii. into Binary

Hex to Binary conversion (4-bit for each digit):

A = 1010

2 = 0010

D = 1101

 (A2D)₁₆ = (101000101101)₂

iii.

   11010

+ 10110

   --------

  110000

11010 + 10110 = (110000)₂

 

iv.

101)	1	0	1	1	1	0	(1001
	1	0	1
	0	0	0	1	1	0
				1	0	1
				0	0	1

Q=1001

R=1

 

 

 

 

 

 

9.      

a.      Write a program in QBASIC to calculate the area of a rectangle using SUB….. END SUB and perimeter of rectangle using FUNCTION... END FUNCTION. [4]

 

DECLARE SUB Area(L, B)

DECLARE FUNCTION Perimeter(L, B)

CLS

INPUT "Enter Length: ", L

INPUT "Enter Breadth: ", B

CALL Area(L, B)

PRINT "Perimeter of Rectangle: "; Perimeter(L, B)

END

 

SUB Area(L, B)

    A = L * B

    PRINT "Area of Rectangle: "; A

END SUB

 

FUNCTION Perimeter(L, B)

    Perimeter = 2 * (L + B)

END FUNCTION

 

 

 

 

b.     Write a program in QBASIC to ask user any word and reverse it using SUB..... END SUB [4]

 

 

DECLARE SUB REV(W$)

CLS

INPUT "Enter any word: ", W$

CALL REV(W$)

END

 

SUB REV(W$)

    FOR i = LEN(W$) TO 1 STEP -1

        R$ = R$ + MID$(W$, i, 1)

    NEXT i

    PRINT "Reversed Word: "; R$

END SUB

 

 

 

 

 

10.  Write a program in QBASIC to ask user any number and check whether it is odd or even using SUB..... END SUB. [4]

 

DECLARE SUB CHECK(N)

 

CLS

INPUT "Enter any number: ", N

CALL CHECK(N)

END

 

SUB CHECK(N)

    IF N MOD 2 = 0 THEN

        PRINT N; " is Even"

    ELSE

        PRINT N; " is Odd"

    END IF

END SUB

 

 

OR,

Write a program in QBASIC to count the occurrence of letter 'a' in the supplied string using FUNCTION…END FUNCTION. [4]

 

DECLARE FUNCTION CountA(S$)

CLS

INPUT "Enter a string: ", S$

PRINT "Number of 'a' in the string: "; CountA(S$)

END

 

FUNCTION CountA(S$)

    C = 0

    FOR i = 1 TO LEN(S$)

        IF MID$(LCASE$(S$), i, 1) = "a" THEN

            C = C + 1

        END IF

    NEXT i

    CountA = C

END FUNCTION