SLC 2072 COMPUTER SCIENCE SOLVED PAPER

SLC 2072 COMPUTER SCIENCE SOLVED PAPER

Group - A

(Computer fundamentals)

    1.      Answer the following questions.

      a)      Define LAN topology. Draw star topology.

      Ans: The arrangement or connection pattern of nodes or computers and other devices of the network is called LAN topology.

      b)      Give any two symptoms of virus attacks.

Ans: The symptoms of virus attacks are:

       i)   Program takes more time to load, fail to load or hang frequently.

      ii) Unexpected messages or images appear suddenly on the screen.

      c)      Write one advantage and one disadvantage of multimedia.

Ans: The advantage of multimedia is:

       i)     One can present ideas, information to others in effective ways.

The disadvantage of multimedia is:

     i)    The cost of developing a multimedia product is high.

      d)     Write any two ways of protecting computer software.

Ans: The two ways of protecting computer software are:

       i)Antivirus Software

       ii)Backup System

      e)      Write any two services of internet.

Ans: The two services of internet are:

     i) WWW (World Wide Web)

     ii)E-mail

      2.      a)Convert as indicated: 

i)(208)₁₀ into Binary 

Converting decimal to binary,

2	208
2	104	0
2	52	0
2	26	0
2	13	0
2	6	1
2	3	0
	1	1

(208)₁₀₌(11010000)₂

ii)(104)₈ into decimal

Converting octal to decimal,

=1*8²+0*8¹+4*8⁰

=1*64+0*8+4*1

=64+0+4

=68

 (104)₈=(68)₁₀

b) Perform the binary calculations:

 i)1011+1101

                1011

            +  1101

               11000

1011+1101=11000

ii)110*11

             110

             *11

             110

       + 110x

          10010

110*11=10010

    3.      Match the following:

Answers:

    a)      Microwave        :           Unguided media

    b)      UTP                   :           Guided media

    c)      UPS                   :           Power protection device

    d)     SMTP                :            Protocol

    4.      State whether the following statements are true or false:

       a)      Walky-talky is an example of full duplex mode.

Ans: False

      b)      Data transfer rate is higher in optical fiber cable than in co-axial cable.

Ans: True

      c)      The computer security refers to hardware security only.

Ans: False

      d)     Sound Card is one of the components of multimedia.

Ans: True

    5.      Write the appropriate technical terms of the following:

a)      A program that can disinfect a file from virus.

Ans: Antivirus software

      b)      A person who steals or destroys other’s data, information, files and program.

Ans: Hacker

      c)      A company which provides the internet facilities.

Ans: ISP (Internet Service Provider)

      d)     A computer which provides services to other computers in a network.

Ans: Server Computer

    

    6.      Write the full forms of:

i)URL              : Uniform Resource Locator

ii)HTTP           : HyperText Transfer Protocol

iii)LAN            :Local Area Network

iv)MODEM     :Modulator-Demodulator

Group – B

(Database)

    7.      Answer the following questions:

       a)      Write any four data types used in Ms-ACCESS.

Ans: Four data types used in Ms-ACCESS are:

     i)     Text                 ii)   Number          iii) Currency        iv) Date/Time

      b)      Define database with example.

Ans: The systematic collection of organized and related information that can be used for different purposes is called database. For example: dictionary and telephone directory.

      c)      What is query?

Ans: A query is one of the objects of MS-Access that allows us to retrieve the desired information from a table or multiple linked tables.

    8.      State whether the following statements are true or false:

a)      A query is used to select fields and records from only one table.

Ans: False

      b)      MS-ACCESS is DBMS software.

Ans: True

      c)      Index decreases the speed of query and sort operations.

Ans: False

      d)     Data in primary key has to be unique and not null.

Ans: True

9.      Match the following:

         a)      OLE                          :       Data type

         b)      Validation Rule        :       Limits the value

         c)      Form                         :       Data Entry

         d)     Indexing                   :       Easy to search

Group - C

( Programming)

     10.  a) What is procedure?

Ans: The separate block of statements used by the module level code and called by any number of times is called procedure.

b) Write any two data types used in ‘c’ language.

Ans: The two data types used in the ‘c” language are:

     i)     int        ii)      float

c) Write down the functions of the following statements:

i) OPEN: It opens a sequential file for one of the three possible operations i.e. reading, writing or appending.

ii) MKDIR: It makes or creates a new directory on the specified disk.

      11.  Re-write the following program after correcting the bugs:

FUNCTION SUM(m,n)

Rem to print sum of two numbers

a=6

b=7

DISPLAY SUM(a,b)

END

FUNCTION SUM(m,n)

S=m+n

S=SUM

END SUM

Debugged program:

DECLARE FUNCTION SUM(m,n)

Rem to print sum of two numbers

a=6

b=7

PRINT SUM(a,b)

END

FUNCTION SUM(m,n)

S=m+n

SUM=S

END FUNCTION

 12.  Write the output of the following program:

 DECLARE FUNCTION Interest(p,t,r)

CLS

LET p=100

LET t=2

LET r=5

LET d=Interest(p,t,r)

PRINT “The simple interest=”;d

END

[possible missing code………]

FUNCTION Interest (p,t,r)

Interest=(p*t*r)/100

End FUNCTION

OUTPUT

If the sub module is missing then error message will be displayed.

Otherwise : The Output will be:

The simple interest = 10

    13.  Study the following program and answer the following questions:

DECLARE FUNCTION Prod(N)

INPUT “Any number”;N

X=Prod(N)

PRINT X

END

FUNCTION Prod(N)

F=1

FOR K=1 TO N

F=F*K

NEXT K

Prod=F

END FUNCTION

                                                                                               

      a)      Write the name of the user defined function used   in the above program.

Ans: The name of the user defined function used   in the above program is Prod.

     b)       Name the loop in the above program.

Ans: The loop in the above program is FOR…NEXT.

    14.  a) Write a program using SUB…..END SUB to display reverse of input-string.

DECLARE SUB REV(A$)

CLS

INPUT “ENTER ANY STRING”;A$

CALL REV(A$)

END

SUB REV(A$)

FOR I= 1 TO LEN(A$)

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

W$=B$+W$

NEXT I

PRINT “REVERSED STRING=”W$

END SUB  

b) Write a program using FUNCTION…END FUNCTION to find area of the triangle.

 DECLARE FUNCTION AREA(B,H)

CLS

INPUT “ENTER BASE”;B

INPUT “ENTER HEIGHT”;H

PRINT “AREA OF TRIANGLE”;AREA(B,H)

END

FUNCTION AREA(B,H)

AREA=0.5*B*H

END FUNCTION

       c)      A sequential data file called “Marks.dat” contains NAME, AGE, CITY, and TELEPHONE fields. Write a program to display all the contents of the data file.

OPEN “Marks.dat” FOR INPUT AS #1

CLS

DO WHILE NOT EOF(1)

INPUT #1, N$, A, C$, T#

PRINT N$, A, C$, T#

LOOP

CLOSE #1

END

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