Solved NPABSON Computer Science 2076

National PABSAN

SECONDARY EDUCATION EXAMINATION BOARD

Qualifying Examination – 2076

COMPUTER SCIENCE

Time: 1 Hours 30 Minutes FM: 50

Group 'A'

[Fundamentals-22 marks]

1. Answer the following question: (5×2=10)

a. What is transmission media? Classify it.

Transmission medium is a pathway that can transmit information from a sender to a receiver through wired or wireless medium on a network.

The types of communication medium are: 

 i) Guided Medium (Bounded or Wired)  

ii) Unguided Medium (Unbounded or Wireless)

b. What is internet? Write down any two services of it.

Internet is an interconnection of several thousands of computers of different types belonging to the various networks all over the world in order to share data and information.

Services:

a)      E-mail (Electronic mail)

b)     FTP (File Transfer Protocol)

c. What is backup? Write down its importance.

Backup is a copy of a file which is used in the event of the original file being corrupted. Backup is essential to computer security system to recover the important data and programs from accidental and intentional harm. They are stored in different storage devices like hard disk, CDs and pen drives. When the data and software gets lost or damaged the backup system helps to recover the lost or damaged data or software from the backup copy of data and software.

d. What is cyber law? When it was passed in Nepal?

The law which governs the legal issues in the cyber space regarding the internet or WWW for digital data processing and transaction is called cyber law.

It was passed on 30^th Bhadra, 2061 B.S.

e. How does virus spread from one computer to other computers?

a)      Sharing infected internal portable disk like floppy disk, pen drive, CDs, etc.

b)     Opening a virus infected email, messages and attached files.

c)      Downloading files and programs form the websites which are not secure.

d)     Exchanging data and information over a network

2. Answer the following question:

a. Perform the conversion as per the direction: (2×1=2)

i. (246) 10 into Binary ii. (A1) 16 into Octal

b. Perform the binary calculation: (2×1=2)

i. 1100×110+1010 ii. 110101÷101

3. Match the following: (4×0.5=2)

a. UPS                                       (b) Virus transfer

b. Pen drive                              (d) Network connection device

c. LAN                                       (a) Computer security

d. HUB                                      (-) Antivirus

(c) Intranet

4. Choose the best answer of the following: (4×0.5=2)

a. Rules use to run a network.

i. Protocol                 ii. Structure                         iii. Technology                   iv. all

b. Band-Width measured in term………………..

i. BPS                         ii. CPS                                 iii. KPS                                iv. None

c. The moving graphic image.

i. Video                      ii. Animation                     iii. Graphics                        iv. Text

d. Which of the following is online business?

i. E-commerce           iii. E-shopping                  ii. E-business                     iv. All

5. Write the appropriate technical terms of the following: (4×0.5=2)

a. A powerful computer which controls and co-ordinates computers connected in a network. Server

b. Message sent electronically through computer network. E-Mail

c. A virus that corrupts system files of operating system. System Infector Virus

d. Educational entertainment done by using multimedia games.  Edutainment

6. Write the full form: (4×0.5=2)

a. FTP – File Transfer Protocol

b. DVD – Digital Versatile Disk

c. CCTV – Closed Circuit Television

d. ISDN – Integrated Services Digital Network

Group 'B'

Database (10 Marks)

7. Answer the following questions: (3×2=6)

a. Write down two objectives of database.

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

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

b. What is primary key? Write down its importance.

A key that uniquely identifies each record in a database is primary key. It is needed because it neither accepts duplicate values now null values.

Importance:

a)      It does not allow duplicate data. 

b) It does not allow null value

c. What is Table?

Table is an object of Ms-Access that stores large volume of data in the form of rows and columns.

8. State whether the following statements are true or false: (4×0.5=2)

a. Every record in a table is unique. False

b. A query is used to select fields and records from one or more tables. True

c. Caption can be up to 2048 characters long. True

d. OLE object cannot store information. False

9. Match the following: (4×0.5=2)

a. Indexed                            (b) Primary interface

b. Form                                              (c) Primary key

c. Unique record                               (-) Sort

d. Table                                (a) Speed up search

(d) Primary storage

Group 'C'

Programming (18 Marks)

10. Answer the following question: (3×1=3)

a. Write two advantages of modular programming.

i) Different programmers can design different program modules independently, which is required in a large and complex program.
ii) It is easy to design code and test the program modules independently.

b. Write down two data type of C language.

char, int

c. Write the function of the following command /statement.

i. CHDIR - It allows QBASIC to change from one directory to another.

ii. FILES - The FILES statement displays the files of the current sub directory or specified sub directory.

11. RE-write the given program after correcting the bugs: (4×0.5=2)

DECLARE FUNCTION VOWELS (W$)

REM TO count number of vowels

INPUT "Enter a word "; W$

PRINT "Number of vowels "; VOWELS (W$)

END

FUNCTION VOWELS (W$)

FOR I =1 TO LEN

M$=LCASE$(MID$ (W$, I, 1)

SELECT CASE M$

CASE IS= "A", "E", "I", "O", "U"

C=C-1

END IF

NEXT I

C=VOWELS

END FUNCTION

Debugged Program

DECLARE FUNCTION VOWELS (W$)

REM TO count number of vowels

INPUT "Enter a word "; W$

PRINT "Number of vowels "; VOWELS(W$)

END

FUNCTION VOWELS (W$)

FOR I = 1 TO LEN(W$)

    M$ = UCASE$(MID$(W$, I, 1))

    SELECT CASE M$

        CASE "A", "E", "I", "O", "U"

            C = C + 1

    END SELECT

NEXT I

VOWELS = C

END FUNCTION

12. Write the output of the following program: (2)

DIM N (4)

DECLARE FUNCTION RES(N (), I)

CLS

FOR I=1 TO 4

READ N(I)

PRINT RES (N ( ), I),

NEXT I

DATA 100, 64, 4, 25

END

FUNCTION RES$ (N$ (), I)

RES=N(I) ^(1/2)

END FUNCTION

Memory Table

I	N(1)	Output
1	100	10
2	64	8
3	4	2
4	25	5

Output

10                         8                            2                            5

13. Study the following program and answer the given questions: (2)

DECLARE FUNCTION COUNT(S$)

CLS

INPUT "Enter a sentence, "; S$

PRINT "Number of space="; COUNT(S$)

END

FUNCTION COUNT(S$)

FOR I=1 TO LEN(S$)

N$=MID$(S$, I, 1)

IF N$=SPACE$(1) THEN C=C+1

NEXT I

COUNT=C

END FUNCTION

a. List the local variable used by above program.

N$, I, C are local variables

b. Write down two library function use by above program.

MID$( ) and SPACE$( )

14. Develop the following program: (3×3=9)

a. Write a program that asks a word and display that is palindrome or not by using SUB..END SUB.

DECLARE SUB REV (S$)

CLS

INPUT "ENTER ANY WORD"; S$

CALL REV(S$)

END

SUB REV (S$)

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

B$ = MID$(S$, I, 1)

W$ = W$ + B$

NEXT I

IF S$ = W$ THEN

PRINT  “WORD IS PALINDROME”

ELSE

PRINT “WORD IS NOT PALINDROME”

END IF

END SUB

b. Write a program which asks radius and display area of circleby using FUNCTION..END FUNCTION.

DECLARE FUNCTION AREA (R)

CLS

INPUT “ENTER RADIUS”; R

PRINT “AREA OF CIRCLE ”; AREA(R)

END

FUNCTION AREA (L, B)

AREA = 3.14 * R ^ 2

END FUNCTION

c. Write a program to create a sequential data file "exam.dat" to store name and marks of three subjects on the basis of user's choice.

OPEN “exam.dat” FOR OUTPUTAS #1

DO

CLS

INPUT “Enter name”; N$

INPUT “Enter marks of three subjects”; A, B, C

WRITE #1, N$, A, B, C

INPUT “Do You want to continue(Y/N)”; CH$

LOOP WHILE UCASE$(CH$)=”Y”

CLOSE #1

END