SOLVED National PABSAN, COMPUTER SCIENCE SEE Pre-Board Examination - 2080

 

National PABSAN, Bagmati Province

SEE Pre-Board Examination - 2080

Time: 2 hours

Subject: Opt. Computer Science

Candidates are required to give their answers in their own words as far as practicable, The figures in the margin indicate full marks for the question.

 

GROUP A [10 X1=10]

 

1. Answer the following questions in one sentence:

 

a) What is a web browser?

Web browser is a computer program that access web pages and displays them on the user’s computer.

 

b) List any two commandments of computer ethics.

Any two commandments of computer ethics.

Do not use a computer to publish fake information.

Do not search the file or record of other people.

 

e) Which data type is used in MS-Access to store address of a person?

Memo data type is used in MS-Access to store address of a person.

 

d) What is a RDBMS?

RDBMS is a type of DBMS that uses a relational model to organize and manage data, allowing users to easily retrieve and manipulate it.

 

c) What is a global variable?

A variable in main module which can be accessed from any module or procedure of a program is known as a global variable.

 

f) Which mode is used to add data items into the already existed data file in QBASIC?

APPEND mode is used to add data items into the already existed data file in QBASIC

 

2. Write appropriate technical terms for the following:

 

a) The amount of data transmitted per second through the communication channel. Bandwidth

 

b) The process of making copies of data or data files to use in the event the original data or data files are lost or destroyed. Backup

 

3. Write the full forms for the following:

 

a) CCTV : Closed Circuit Television

 

b) SIM : Subscriber Identity Module

 

GROUP B (12 X 2=241

 

4. Answer the following questions:

 

a) What is computer security? Write any two software security measures.

 

 

Computer security refers to protecting computer and its content from damage, theft or misuse and action to prevent such incidents.

Any two software security measures are: Password and Backup

 

b) List four ways to stay safe on social networks.

Any four ways to stay safe on social networks

·       Pick strong passwords and update them frequently. 

·       Report harassment or inappropriate content.

·       Pause before you post.

·       Look before you click. 

 

e) What is m-commerce? Give two examples of digital wallets used in Nepal.

M-Commerce refers to the process of buying and selling of goods and services through wireless handheld devices such as smartphones, tablets or personal digital assistants (PDAs).

Any two examples of digital wallets used in Nepal are e-sewa and Khalti.

 

d) What is cloud computing? Write any two examples of Al.

Cloud computing is a technology that allows users to access and use of computing resources, like servers and software, over the internet.

Any two examples of Al are: speech recognition (like Siri, Microsoft Cortana, Amazon Echo, Google Home etc.),

And self-driving cars.

 

e) Define ring topology. Write its two advantages.

The type of topology in which each computer is connected to another computer with the last one connected to the first is called ring topology.

Any two advantages of ring topology are:

l In this topology all computers, in close loop, act as a client or server to transfer the information.

l Transmitting network is not affected by high traffic or by adding more nodes.

 

f) What is a foreign key? Write two properties of primary key.

A foreign key in MS Access is a field that establishes a relationship between two tables by referencing the primary key of another table.

Any two properties of primary key are:

It sets the relationship between tables.

It reduces and controls duplication of record in a table

 

g) Write any two differences between data sorting and data filtering.

 

Sorting	Filtering
The process of arranging all the records in a table either ascending or descending order based on field or fields is known as sorting.	Filtering is the process of viewing required record of a table that matches the specifies criteria.
Sorting affects the entire dataset.	Filtering only affects the data that is displayed.
Sorting is often used to make data easier to read.	Filtering is used to find specific information.
Sorting can be done in ascending or descending order.	Filtering has various criteria that can be applied.

 

 

 

 

h) Write a difference between database and DBMS. Give one example of manual database.

Database	DBMS
A collection of systematically organized inter-related data is called a database.	Database management system (DBMS) is a computerized system that stores data, processes them and provides information in an organized form
Besides computers, databases can even be maintained in physical ledgers, books, or papers.	In a database management system (DBMS), all the records are maintained only on a computer.
In the case of the databases, very less information can be modified at a time.	In the database management system (DBMS), a lot of information can be changed at one time (as it can have many users using it at the same time).
Eg. Dictionary, Marks Ledger, Telephone Directory, Attendance Register etc.	E.g. MS-Access, Oracle, MS-SQL Server, MySQL, PostgreSQL etc

Telephone Directory is an example of manual database.

 

i) What is a Form? Write two uses of a form.

Form is one of the MS-Access database objects which provides graphical interface to view, modify and add data in a table or multiple linked tables.

Any two uses of a form are:

·       Forms provide an easy-to-use interface for data entry and manipulation, improving data accuracy and completeness.

·       Forms can include validation rules to ensure data quality and prevent errors.

 

5. Write down the output of the given programs. Show with dry run in a table.

DECLARE SUB Display(S$)

CLS

S$=”TOEPOHSDRA"

CALL Display (S$)

END

SUB Display(S$)

LET I=48

FOR C=1 TO 4

P=I MOD 7

R$=R$+ MID$(S$, P, 1)

I=I-1

NEXT C

PRINT R$

END SUB

Dry Run

S$	I	C=1 TO 4	P=I MOD 7	R$=R$+ MID$(S$, P, 1)	I=I-1	PRINT R$
TOEPOHSDRA	48	1 TO 4  yes	48 MOD 7= 6	H	48-1=47	HOPE
		2 TO 4 yes	47 MOD 7 = 5	HO	47-1=45
		3 TO 4 yes	46 MOD 7= 4	HOP	45-1=44
		4 TO 4 yes	45 MOD 7 = 3	HOPE	44-1=43
		5 TO 4 no Loop exits

The output of a program is:

HOPE

 

6. Re-write the given program after correcting the bugs.

 

REM Program to add records to an existing file "Student.dat"

OPEN "Student.dat" FOR APPEND AS #1

DO

CLS

INPUT "Enter name: "; N$

INPUT "Enter Address: "; Ad$

INPUT "Enter Total Marks: "; TM$

COPY #1, N$,  Ad$, TM

INPUT "Do you want to add more records? Press Y or N: "; CH$

LOOP WHILE UCASE$(CH$) < > “Y”

CLOSE "Student.dat"

END

 

Debugged Program

REM Program to add records to an existing file "Student.dat"

OPEN "Student.dat" FOR APPEND AS #1

DO

CLS

INPUT "Enter name: "; N$

INPUT "Enter Address: "; Ad$

INPUT "Enter Total Marks: "; TM

WRITE #1, N$,  Ad$, TM

INPUT "Do you want to add more records? Press Y or N: "; CH$

LOOP WHILE UCASE$(CH$) = “Y”

CLOSE #1

END

 

7. Study the given program and answer the questions it follows.

DECLARE FUNCTION Calculate (X,Y)

CLS

INPUT "Enter a multi-digit number"; N

LET S = Calculate (N,T)

PRINT "The sum =”; S

END

 

FUNCTION Calculate (X,Y)

WHILE X < > 0

R=X MOD 10

Y = Y + R

X=X\10

WEND

Calculate = Y

END FUNCTION

a) List formal parameters and real parameters of procedure Calculate'.

            The formal parameters are X and Y and real parameters are N and T.

b) What is the purpose of the above program?

            The purpose of the above program is to display the sum of digit of an input number.

 

8. Perform the following as indicated:

 

a) (11101011)2=(?)8

b) (65)10=(?)2

c) (11101)2+(11011)2-(11110)2

d) (111011)2¸(11)2

 

GROUP C

9. (a) Write a program in QBASIC to find out sum of three numbers using SUB procedure and average of three numbers using FUNCTION procedure.

DECLARE SUB SUM(A, B, C)

DECLARE FUNCTION AVG(A, B, C)

CLS
INPUT “Enter first number”; A

INPUT “Enter second number”; B

INPUT “Enter third number”; C

CALL SUM(A, B, C)

PRINT Average of three numbers=”; AVG(A, B, C)

END

SUB SUM(A, B, C)

S=A+B+C

PRINT “Sum of three numbers=”; S

END SUB

 

FUNCTION AVG(A, B, C)

AVG=(A+B+C)/3

END FUNCTION

(b) A sequential data file, "record.dat." contains several records with data items name, address, age, and phone number. Write a program to display the records of students whose age is greater than or equal to 18.

 

OPEN “record.dat” FOR INPUT AS #1

CLS
PRINT “NAME”, “ADDRESS”, “AGE”, “PHONE NUMBER”

WHILE NOT EOF(1)

INPUT #1, N$, A$, AG, PN

IF AG>=18 THEN PRINT N$, A$, AG, PN

WEND

CLOSE #1

END

 

10. Write a program in C language to input length of three rods and display whether the triangle can be formed by those rods or not. [4]

 

#include <stdio.h>

int main() {

    float a, b, c;

    printf("Enter the length of rod for side 1: ");

    scanf("%f", &a);

    printf("Enter the length of rod for side 2: ");

    scanf("%f", &b);

    printf("Enter the length of rod for side 3: ");

    scanf("%f", &c);

    if (a + b > c && a + c > b && b + c > a)

{

        printf("The triangle can be formed by rods.\n");

    }

else

{

        printf("The triangle cannot be formed by rods.\n");

    }

    return 0;

}

OR

Write a program in C language to declare whether the given number is 'Positive', 'Negative' or 'Zero'.

#include<stdio.h>

#include<conio.h>

int main()

{

int n;

printf("Enter any number: ");

scanf("%d", &n);

if(n>0)

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

else if(n<0)

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

else

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

return 0;

}