S.P.9 KCSE COMPUTER STUDIES PAPER 1 PAST QUESTIONS AND ANSWERS

SAMPLE PAPER 9

COMPUTER STUDIES PAPER 1

451/1

SECTION A (40MKS)

ALL QUESTIONS IN THIS SECTION

1. Give any two differences between fourth and fifth computer generations (2mks)

2. List three ways in which computers are used in education.  (3mks)

3. a) Define the term booting (Imk)

b)Explain the difference between cold and warm booting.  (2mks)

4.   State the use of

a)Tab key   (Imk)

b) home key  (Imk)

5.  Distinguish between

(a) Web master and web designer ((Imk)

(b) Parallel and serial cables   (Imk)

6 a) Define a computer memory (Imk)

b) Give three examples of special purpose memories  (1 ½ mk)

c) Explain the difference between logical and physical files  ( 2mks)

7.  Perform the following binary operations giving your answer in decimal

a) 11101.11

11111.11 + (2mks)

b) 1111.11

1101.01 –   (2mks)

8. a) What is search engine ? (lmk)

b) State three examples of search engine (1 ½ mks)

9.  a), identity the program control structures represented by the flowchart segments above

i. ………………………………………..   (1 mk)

ii. ………………………………………  (1 mk)

iii. ………………………………………..  (1 mk)

b. Differentiate between control structure (i) and (ii)  (I mk)

10.  You are provided with the worksheet below study it and answer the questions that follow

a) If cell Dl represents the total value of books pens and pencils. Determine the formulae for the total value of cell Dl used.  (1 mk)

b) If the formula of cell Dl is copied to cell D3. Determine resulting value of cell D3 (lmk)

c) Give the type of cell referencing that is used in cell D3.  (1mk)

11.  State the application areas of

a) CAM  (1mk)

b) CAD  (lmk)

12.  E-mail is becoming preferable means of communication these days, give two Advantages of adopting this technology in work place and at home (2mks)

13  .Give two ways of protecting data in a networked environment. (1mk)

14.  Highlight any four effects of the internet on society today.  (4mks)

SECTION B (60MKS)

ANSWER QUESTION 15, IS COMPULSORY AND ANY OTHER THREE QUESTIONS FROM THIS SECTION.

1 5 a) Define the terms

i) Flowchart   (Imk)

ii Algorithm   (Imk)

iii) Pseudo code (Imk)

b) The gross salary of employees of Kenya Airways sales agency is based on basic salary and other additional benefits, which is computed as follows: basic salary and other additional benefits, which

i) Employees who have worked for the company for more than five years receive an additional pay of 10% to their basic salary

ii) Monthly salary bonus based on monthly sales of air tickets are rated as shown in the table.

Draw a flowchart for a program that would be used to compute the gross salary then output each employee’s basic salary and show all the benefits  (9mks).

c) i) What is an array ? ( Imk)

ii) State two properties of an array   (2mks)

16 a) i) What is information system ? (Imk)

ii)Explain three purpose of information system. (3mks)

ii) With use of a diagram explain the development of system life cycle (6mk)

b) i) Define system entropy  (Imk)

ii) State two main factors that may lead to system entropy.   (2mks)

c) Explain why HTML is not a true programming language  (2mks)

17 a) i) Define electronic point of sale terminal? (1mk)

ii) Explain two advantages of using this system. (2mks)

iii) Give an application areas of this system. (1mk)

b) List four elements of a network   (2mks)

c) State three types communication media of the following

i) bounded   (1 ½ mks)

ii) unbounded communication   (1 ½ mks)

d) Explain two advantages and two disadvantages of unbounded communication   (4mks)

e) Give any two communication devices required by a network to be fully operational (2mks)

18 a) State and explain the role of the following

i) Software engineer   (2mks)

ii) Computer trainer (2mks)

b) Explain the effect of information communication technology in

i) Job opportunities (3mks)

ii) Environment (3mks)

iii) Automated production (3mks)

c) Distinguish between sequential and indexed sequential as used in file organization

(2mks)

19 a) State the application area of

i) Magnetic ink character recognition (1mk)

ii) Optical mark reader (Imk)

b) Define the terms

i) Byte   (1 mk)

ii) Nibble  (Imk)

c) List any four objects used in the database (2mks)

d) Explain any two features of word processor (2mks)

e) Use two’s complement method to perform the binary operation below

37₁₀ – 17₁₀  (3mks)

f) Write the BCD code for 29 ₁₀  (Imk)

g) What is distributed data processing ? (Imk)

ii) Explain two advantages of distributed data processing in an organization   (2mks)

iii) State one problem of adopting this system in an organization. (1mk)

MARKING SCHEME

SAMPLE PAPER 9

451/1

(1)  Fourth generation fifth generation

• high memory capacity  –  very high memory

• cost high –  very cost

• support task operation one after a tia .. –  support parallel processing

• not based logical inference operation –  make use of artificial intelligence

• make little use of artificial intelligence

(2)  Accept

• computer aided instruction (CAM)

• computer assisted learning (CAL)

• e-learning

(3)  Booting is the starting up of computer
by loading up instruct from the memory

b) cold -starting a computer when power is originally off warm – restarting a computer when

power is originally on.

(4)  Tab key is movement of the cursor at a given set intervals of five spaces at end the cursor position

b) home key moves the cursor to the beginning of current line.

(5)  Web designer develops and maintains websites and their serve while a web master is responsible for all technical aspect of a websites e.g performance issues such as access and approving sites contents, access rights of contents etc.

b) parallel cables transmits data faster but in a short distance unlike serial slow but transmit data in long distance.

(6).

(a) is a unit of a computer, instruction.

(b)

• buffers

• registers

• cache memory

(c) Logical files – viewed terms of data items it contain and detail of what processing operation performed on them.

Physical files viewed in terms of how data is a :

 7  a)  11101.11

 11111.11 +

 111101.10

 =(61.5)₁₀

b)  1111.11

1101.01 –

10.01 =(2.5)₁₀

8.  a)  Search engine are special websites that maintain a list of hyperlinks that

enables to transverse from one hyperlink to another when they find a new material.

• Examples of search engine are

• goggle
• hotmail
• yahoo

 Enter salary, sales

Experiences  Yes

 Bonus =

salary x 10

No

Sales 
50,000 Yes

No Bonns 1 = sales *

25/100

Yes   Sales

  25,000

Bonus = sales

* 10/100 No

Bonus = sales *

  15 / 100

Gross salary = salary + bonus + bonus 1 + bonus 2 + bonus 3

Print Gross salary ,Bonus,

Bonus 1,

Bonus 2,

Bonus 3

No   Exit

Yes

Stop

1. Start

Q15(b)

Enter salary, sales

Experience Yes

  Bonus = Salary x 10

No

Sales Yes

50,000 >

Bonus =sales 25/100

No

Sales

Yes 25,000<

No

Bonus 3 = sales

* 10/100 Bonus 2 = sales

* 15/100

Stop

a)  i)  Repeat.. until

ii)  For .. Do

1. If .. Then.. Else

1. In (i) the condition is tested at the end of loop and hence loop statement is executed once (ii) the condition is tested at the entry of the loop and the program exists if the condition is evaluated to false.

10.  a)  = sum (A2:C2)

b)  D2 = 1095

11.

1. CAM – Assembly in engineering products / vehicles
2. CAD- designing engineering product and archectural drawings / electrical circuit board, motherboard , textile pattern design.

• Convenience /cost / fast
• – Use of passwords / sign in or login.
  • Restriction to unauthorized access
• – Job creation
  • Cultural effect
• –  Easy access of information

  –  Drug abuse / sex abuse/

  a)  i)  diagrammatic representation of an algorithm

   ii)  Steps defining on how to solve a problem

   iii)  Step defining of solving a problem which is close to real programming language.

  b)

   

  c)  i)  is a set of data items of the same type grouped together using identifiers.

   ii)  Properties of arrays.

  • arrays can be of any dimension
  • arrays can be of a character / integer
  • array can be puckered where character are packed.
• a)  i)  information system is arrangement of people, data process and information that

  work together to support and improve operation activities e.g. business and decision making.

ii)  Purpose of information system

• Support and enhance information processing and communication.
• Help in decision making by collecting operation data analysis, report generation.
• Enhances sharing of information

iii)  

• New opportunity
• Problems
• Directives

iv

1- problem recognition and definition

2- information gathering

3 requirement specification

4 system design

5 system construction (coding)

6 implementation and testing

7 review and maintenance

b)  i)  system entropy – is a system decay naturally overtime.

ii)  changes in technology, new management policies, changes in new requirement

17.  a)  i)  electronic device used in retail store to input and output data at the point

where a sales are transacted

ii)  advantages of EPOS

•  ensure correct prices are used at the check out cover.

•  faster in data processing

•  efficient

•  enhances better control of business as stock is controlled

iii) Super market ,big companies

b)

•  communication media

•  network software

•  communication devices

•  data signals

c)  i)

•  twisted pair cables

•  coaxial cables

•  fibre optical cables

ii)

•  Microwave

•  Satellite

•  Radio transmission

d) `  advantages

• flexible in operation

• can cover in a large geographical area

• can access a remote areas via satellites

disadvantages

• it is relatively difficult to establish and configure

• the initial cost is very high

 18.  a)  i)  Software engineer

•  develop system and application software

•  develop user and technical documentation for new software

•  maintain and update the software to meet day to day requirement

1. Computer trainer.

•  train people on how to use computers

•  develop training reference materials

•  guide learners on how to use and acquire knowledge through research.

•  Prepare learners with ICT examinations

b)  effect of ICT on

i)  job opportunities

•  job creation i.e. new jobs are created

•  job replacement i.e. replacing of computer illiterate people / workers

•  displacement of jobs that were formerly manual

ii)  environment

•  energy

•  consumption

•  paper consumption

•  radiation

•  pollution

1. Automated production

•  assembly of vehicles in plants

•  oil refineries

•  food processing

•  increased production

•  creation of unemployment

1. Sequential – records are stored and accessed in a particular order sorted using a key field.

   Whereas indexed sequential uses both method random and sequential records are arranged in key sequence and position marked with indexes

    

 19.  a)  i)  cheque processing /survey

ii)  marking of examination /bank

b)  i)  byte – group of 8 bits

ii)  nible – group of 4 bits

• •  tables

  •  forms

  •  reports

  •  queries

  •  macros

  •  modules

   

• •  numbering

  •  bulleting

  •  spacing

  •  alignment

  •  indentation

• i)  00010110
• (0010 1001)
• i)  data processing technique where data processing is divided into groups

  physically located at different sites but connected to a central location.

  ii)  advantages:

    Errors easily corrected

    Better reliability

    Low cost

   Enhanced security

    System failure does not affect others

    Encourages effective decision making

1. Disadvantages / problems

    users have to be trained

    standards are difficult to maintain

    requires extra cost i.e. expensive

    there are programming techniques with micro- computers and mini- computers