S.P.10 KCSE COMPUTER STUDIES PAPER 1 PAST QUESTIONS AND ANSWERS - EcoleBooks (2025)

SAMPLE PAPER 10

COMPUTER STUDIES PAPER 1

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SECTION A ( 40 MARKS)

Attempt all questions in this section.

1. Explain the meaning of the following transmission impairments. (2mks)

a) Attenuation.

1. Cross-talk

2. a) Define the term file organization. (1mk)

b) Explain two methods of file access. (2mks)

3. List four number systems that the design and organization of a computer may depend on. (4mks)

4. Explain the meaning of the following terms as used in computer communication (2mks)

a) Modulation

b) Demodulation

5. Using one’s complement, calculate 11011₂-111₂ and leave your answer in binary notation. (4mks)

6. List three types of computers that are classified according to the type of signal they use when functioning. (3mks)

7. In relation to DTP, explain the meaning of (2mks)

a) Pasteboard

1. Masterpage

8. What is the main function of a primary key in a database. (1mk)

9. Apart from a computer, give three other elements that are needed in order to connect to the internet. (3mks)

10. a) Define the term virtual reality. (1mk)

b) Give three components of a virtual reality system. (3mks)

11. Highlight any two ways in which computers are used as industrial systems. (2mks)

12. Indicate the type of cell reference depicted by the following. (3mks)

a) $H$5

1. H5
2. H $ 5

13. List three components of a spreadsheet. (3mks)

14. State two documents that are needed during the process of mail merging. (2mks)

15. State any two components of a world wide web. (2mks)

SECTION B ( 60 MARKS)

Answer questions 16 and any other three questions from this section

16. a) Define the following terms as used in programming. (2mks)

i) Assembler

ii) Pseudo-code

b) With the aid of flowchart segments, highlight two differences between the REPEAT….UNTIL and WHILE…..DO statement structures. (4mks)

c) Give the name and use of the flowchart symbol below. (2mks)

A

A

1. Name …………………………………………………………………………………
2. Use

d) It is required that numbers from 5 to 100 in the series 5,10,15….100 are multiplied and the product displayed. Design a flowchart for solving the problem. (7mks)

17. a) The following diagram shows the stages of developing an information system.

REVIEW 7

IMPLEMENTATION 6

CONSTRUCTION 5

DESIGN 4

REQUIREMENT 3

SPECIFICATION

INFORMATION 2

GATHERING

PROBLEM 1

RECOGNITION

i) List any four methods that can be used to achieve the second stage in above. (4mks)

ii) List any four areas that have to be designed at the fourth stage. (4mks)

b) Explain the meaning of the following system characteristics. (4mks)

i) Entropy

ii) Controls

c) State the three functions of an information system. (3mks)

18. The diagram below shows various entities, their attributes and the relationship among them.

i)

CUSTOMER 1

CUSTOMER 2 RESIDENCE

CUSTOMER 3

ii) CUSTOMER 1 CUSTOMER 1 ID

CUSTOMER 2 CUSTOMER 2 ID

CUSTOMER 3 CUSTOMER 3 1D

iii) CUSTOMER 1 COOKING FAT

CUSTOMER 2 SOAP

CUSTOMER 3 TOOTHPASTE

a) Define the terms. (6mks)

i) Entity

ii) Attribute

iii) Relationship

b) Indicate the type of relationship depicted by the diagram above. (3mks)

i)

ii)

iii)

c) (a) Write the acronym DBMS in full. (1mk)

(b) State any three functions of a DBMS. (3mks)

d) List any three database models. (3mks)

19. a) State three characteristics of RAM. (3mks)

b) The capacity of a computers memory is 128MB. Calculate the maximum number of nibbles the memory can support. (4mks)

c) List any (5mks)

(i) Three pointing input devices

(ii) Two digitizing input devices.

d) State any three softcopy output devices. (3mks)

20. The following diagrams shows various transmission media for networking to computers.

a) Name the transmission media shown in the diagrams above. (3mks)

i) ………………………………………………………………………………………………..

ii) ………………………………………………………………………………………………..

iii) ………………………………………………………………………………………………..

b) State any two advantages of using medium (i) over medium (iii) (2mks)

c) Explain the difference between a bridge and a gateway.

d) Give the use of the following networking devices. (6mks)

i) Network interface card(NIC)

ii) Router

iii) Repeater

iv) Explain the difference between a data Terminal Equipment (DTE) and Data Circuit – terminating Equipment (DCE) (2mks)

MARKING SCHEME

SAMPLE PAPER 10

451/1

1. a) Progressive decrease in magnitude and energy as a signal moves along a

transmission medium.

1. Interline interference (Each 1 m x 2 = 2mks)

2. a) The systematic arrangement of files in a computer secondary memory. (1mk)

b)

i)Direct file access

ii) Indexed

iii) Serial – indexed (2mks)

3. – Hexadecimal

– Octals (Each 1 mk x 4 = 4mks)

– Decimal

– Binary

4. a) Changing of the digital data to analog data.

b) Changing of the analog data back to digital data.

5. 1011₂
 – 111₂ 00100₂

– 000₂

00100₂ (4mks)

1. Digital computer

   Analog computer

   Hybrid Computer (Each 1 mk x 3 = 3mks)
   

2. a) An area in a DTP package where work is organized before placing it on the

   printable area. (1mk)

b) pages used for general organization and format of a publication (1mk)

8. Used for relating records of similar characteristics within a database (1mk)

9. – Nic (Network Interface Card)

– Internet Service provider (Each 1 mk x 3 = 3mks

– Internet O/s

10. a) A situation / condition in which a person becomes psychological immersed in

an artificial environment generated by a computer system. (1mk)

b) – Headgear

– Gloves

– Body suit

– Virtual reality software.

11. – Process control

– CAD / CAM (Any two well highlighted each 1 mk x 2 = 2mks)

– Simulation.

12. a) Absolute

b) Relative (Each 1 mk x 3 = 3mks)

c) Mixed

13. – Work sheet

– Database

– Graphs

14. – Data source

– Main document

15. – LAN

– WAN (2mks)

16. a) i) A programming language that translates an assembly language into

machine language. (1mk)

ii) A set of statements written in a readable language (English – like phrases) expressing the processing logic of a program . (1mk)

b) REPEAT – UNTIL WHILE – DO

  No No Stop

In repeat – until the statements are executed before the condition is tested while in the while do the condition is tested before the statements are executed .  4 mks

c) i) Connectors

ii) Used to join the logical flow (2mks)

17. a) i) Study of available documents

– Interview

– Questionnaires (Each 1 mk x 4 = 4mks)

– Observation

– Automated methods

ii) Flowcharts

• Data flow diagrams
• Entity relationship models
• Structured charts

1. Entropy

   Controls (Well explained each 2 mks x 2 = 4mks)

2. – Supporting information processing

• Help in decision making

– Enable sharing information (Each 1 mk x 4 = 4mks)

18. a) i) Data entered in a particular column of a record

ii) Features of data e.g. format.

1. Data of related features / attributes (Each 2 x 3 = 6mks)

1. Many – to – one

   One – to – one

   Many – to – many

2. i) Database management systems (1mk)

   1. – Keep data / store data

      – Process data

      – Analyse and output information (Each 1 mk x 3 = 3mks)
      

d) – Flat model

– Related model

– Hierarchical model 1 x 3 = 3mks

19. a) – Volatile

– Limited

– Very expensive

b) 128 = 16

8 2 = 8 Million nibbles (4mks)

c) i) – Joystick

– Mouse

– Light pen

ii) Digitiser

1. LED

   Speakers (3mks)

   Monitors

20. a) i) Twisted pair

ii) Coaxial (Each 1 mk x 3 = 3mks)

1. Fibre optic

b) – Installation equipment is cheap.

– It is readily available in most building (2mks)

c) Bridge – a network device that selectively determine the appropriate network segment for which a message is meant while a gateway is any device configured to provide access to wide area networks or internet.

d) NIC– Creates physical link between the computer and the transmission media.

Router – Interconnects different networks and directs the transfer of data packets from source to destination.

Repeater – boosts a weakening signal (6mks)

e) DTE is any device e.g. a computer workstation on a network, while a DCE ends /

marks the end of physical network circuit. (2mks)