SOLVED KAVRE PABSON - SEE PRE QUALIFYING EXAMINATION 2080 - COMPUTER SCIENCE

 

SOLVED KAVRE PABSON - SEE PRE QUALIFYING EXAMINATION 2080 - COMPUTER SCIENCE

Subject :Computer Science

Time: 1 hr. 30 min

Full Marks:50

Class: X

Group-A

1. Very short answer questions:

 

a) What is communication?

Ans: Communication is sending and receiving information between two or more persons.

 

b) Which data type is used to store picture in Ms-Access?

Ans: The data type which is used to store picture in Ms-Access is OLE.

 

c) Define computer security.

Ans: Computer security means protecting computer and its content from damage, theft or misuse and action to prevent such incidents

 

d) What is E-commerce?

Ans: E-commerce refers to the buying and selling of goods or services using the internet.

 

e) What is formal parameter?

Ans: Parameters are variables that will receive data (arguments value) sent to the procedures (SUB program and FUNCTION).

 

f) Define C-programming.

Ans: C language is a structured programming language that divides program into many functions.

 

2. Write appropriate technical terms for the following:                          [2×1=2]

 

a) The mode of data communication in which data can be transferred in both directions at a time.

Full Duplex Mode

 

b) A unique numerical identifier for every device or network that connects to the internet. IP Address

 

3. Write down the full form of the following:                                                        [2×1=2]

 

a) SMTP - Simple Mail Transfer Protocol.

b) MODEM - Modulator-Demodulator.

 

Group-B

 

4. Short Answer Questions: 9×2=18

 

a) Distinguish between STP and UTP.

Ans: The difference between shielded and unshielded twisted pair cables are:

STP	UTP
UTP cable is a twisted pair cable with wires that are twisted together	It is enclosed within a foil or mesh shield.
the UTP cable is used to establish the connection within a short distance, like a home or small industry.	Generally, it is used to establish the connection for enterprises over a long distance.

b) Explain about star topology with the help of diagram.

Ans:

The network topology which connects all nodes to central device called hub/switch through a cable is called star topology. It provides fast performance and low network traffic. The failure of one node does not affect the rest of the nodes.

Diagram

 

c) Write about opportunities and threats in social media.

Ans:

Opportunities of using social media

a)     It creates awareness and innovate the way people live

b)     Social media let us share anything with others around the world.

c)     It keeps us informed about the world.

d)     It creates brand exposure for business to the largest audience.

Threats of using social media

a)     Personal data and privacy can be easily hacked and shared on the internet.

b)     More chances of creating fake accounts.

c)     Negative impact on the health.

d)     Decrease the working efficiency of people.

e)     Spreading false or unreliable information.

 

d) Define table in a database? Explain why it is important.

Ans: Table is a database object that stores a collection of related data organized in rows and columns, where each row represents a record and each column represents a field or attribute of that record.

It is important because entire data is managed and kept in a table for the future retrieval process. It makes sure that the information stays accurate and consistent.

 

e) Distinguish between validation rule and validation text.

Ans: The difference between validation rule and validation text is

Validation Rule	Validation Text
A rule that specifies the valid values or ranges of values that can be entered in the field.	A message that appears if a user enters invalid data in the field.

 

 

f) What is an online payment (electronic payment)? Make a list most common payment platforms used in Nepal.

Ans; Online payment refers to the payment for buying goods or services through the Internet using different online payment gateway. E.g. e-Sewa Nepal, i-Pay, Khalti, e-banking, etc.

 

g) "Artificial Intelligence is threat to humans". Give your opinion.

Ans: AI can be a threats to human. AI could become uncontrollable and pose a threat to humanity. This could happen if AI systems become more intelligent than humans and begin to act on their own, without human guidance or control. AI could be used for bad things like cyber attacks or making weapons that can decide on their own who to attack, causing a lot of harm. It's like giving a sharp knife to a toddler - bad idea

 

h) What is global variable? How it is declared?

Ans: Variables which are declared outside the procedure and whose values can be accessed from any procedure or module are called global variables.  It is declared by using SHARED, DIM SHARED or COMMON SHARED statement.

 

i) Define built in function? Explain about the use of LEN() function in QBASIC.

Ans: Built-in functions are  readymade functions provided by QBASIC. LEN ( ) function returns the number of characters in a string or the number of bytes required to store a variable.

5. Write down the output of the following program with dry run table.

DECLARE SUB REG(M,N$,T)

CLS

A=1

X$=”PABSON”

CALL REG(A,X$,T)

END

SUB REG(M,N$,T)

FOR I=LEN(N$) TO 1 STEP-1

PRINT MID$(N$,I,M)

M=M+1

NEXT I

END SUB

 

Dry Run

A	X$	M	T	I=LEN(N$) TO 1 STEP-1	PRINT MID$(N$,I,M)
1	PABSON	1	0	6 TO 1 STEP-1 Yes	MID$(PABSON,6,1) N
		2		5 TO 1 STEP -1 Yes	MID$(PABSON,5,1) ON
		3		4 TO 1 STEP -1 Yes	MID$(PABSON,4,1) SON
		4		3 TO 1 STEP -1 Yes	MID$(PABSON,3,1) BSON
		5		2 TO 1 STEP -1 Yes	MID$(PABSON,2,1) ABSON
		6		1 TO 1 STEP -1 Yes	MID$(PABSON,1,1) PABSON
		7		0 TO 1 STEP -1 No  Loop Exits

The output of the program is :

N

ON

SON

BSON

ABSON

PABSON

 

 

 

 

 

6. Re-Write the given program after correcting the bugs:

 

DECLARE FUNCTION RESULT$(X,Y)

CLS

INPUT “Enter marks in math:”, M

R$=RESULT$(X,N)

PRINT M$

END FUNCTION

 

FUNCTION RESULT$(X,Y)

IF X>=40 AND Y>=40 THEN

RESULT$ = "Pass"

ELSE

RESULT$ = "Fail"

END IF

END SUB

 

Debugged Program

DECLARE FUNCTION RESULT$(X,Y)

CLS

INPUT “Enter marks in math and science:”, M, N

R$=RESULT$(M,N)

PRINT R$

END

 

FUNCTION RESULT$(X,Y)

IF X>=40 AND Y>=40 THEN

RESULT$ = "Pass"

ELSE

RESULT$ = "Fail"

END IF

END FUNCTION

 

7. Study the following program and answer the given questions:

 

DECLARE FUNCTION MATH$(R)

CLS

DIM SHARED P

INPUT "Enter first number:"; P

INPUT "Enter second number:"; C

Y$ = MATH$(C)

PRINT Y$

END

 

FUNCTION MATH$(R)

F=100 MOD R

IF 20 MOD P > 3 AND F < P THEN

MATH$=”True”

ELSE

MATH$=”False”

END IF

END FUNCTION

a) Variable P remained uncalled in the main module. Why?

Ans: Variable P remained uncalled in the main module because P is declared as global variable and its value can be accessed by MATHS$ ( ) function without passing the value.

 

b) Find the output if the user supplies P=9 and c=4 running the program.

Ans: The output of the program if the user supplies P=9 and c=4 running the program is:

False

 

Dry Run

P	C	R	F=100 MOD R	20 MOD P > 3 AND F < P	PRINT Y$
9	4	4	100 MOD 4 =0	20 MOD 9 >3 2>3 AND 0<9 Yes AND No No	False

 

Group-C

 

8. Convert as instructed:

 

a) (B7D)16=(?)8

b) (645)10=(?)16

c) (10101)2 ×(110)2

d) (1110101)2 × (110)2

 

9. a) Write a program in QBASIC to input length and breadth of a rectangle and calculate area using function-procedure and perimeter using sub-procedure.[4]

 

DECLARE FUNCTION AREA (L, B)

DECLARE SUB PER (L, B)

 

CLS

INPUT “ENTER LENGTH”; L

INPUT “ENTER BREADTH”; B

PRINT “AREA OF RECTANGLE=”; AREA(L,B)

CALL PER(L,B)

END

 

FUNCTION AREA (L, B)

AREA = L * B

END FUNCTION

 

 

SUB PER (L, B)

P = 2 * (L + B)

PRINT “PERIMETER OF RECTANGLE=”;P

END SUB

 

 

 

 

 

b) A sequential data file named “user.dat” has data under the fields [ Name, Age, Sex, Contact No and Address ]. Write a program that displays the record of those users whose age is more than 35.   [4]

 

OPEN “user.dat” FOR INPUT AS #1

CLS

PRINT “Name”, “Age”, “Sex”, “Contact No.”, “Address”

WHILE NOT EOF(1)

INPUT #1, N$, A, S$, C, D$

IF A>35 THEN PRINT N$, A, S$, C, D$

WEND

CLOSE #1

END

 

 

 

10. Write a C program to find sum of the numbers from 22 to 32 using FOR loop.

 

#include <stdio.h>

int main ( )

{

   int i, sum = 0;

   for (i = 22; i <= 32; i++) {

       sum += i; 

   }

   printf("The sum of the numbers from 22 to 32 is: %d\n", sum);

   return 0;

}

 

 

Write a program in C that asks a number and check whether it is positive, negative or zero.

 

#include <stdio.h>

int main()

{

    int number;

    printf("Enter a number: ");

    scanf("%d", &number);

    if (number > 0)

{

        printf("%d is positive\n", number);

    }

else if (number < 0)

{

        printf("%d is negative\n", number);

    }

else

{

        printf("%d is zero\n", number);

    }

 

    return 0;

}