K.C.S.E TOPICAL REVISION SERIES
FORM 1-4 2018
COMPUTER STUDIES
This booklet contains questions and answers from every topic from
form one to form four. The questions have been very well explained
and illustrated. Learners will find it easy to revise using this booklet.
Teachers can also use this booklet to set exams and prepare marking
schemes.
Buria Erick
, K.C.S.E TOPICAL REVISION SERIES 2018
COMPUTER STUDIES
INTRODUCTION TO COMPUTERS
1. (a) Clearly define a computer
- A computer is an electronic device that operates (works) under the control of programs stored
in its own memory unit
- An electronic device that accepts data, as input and transforms it under the influence of a set of
special instructions called programs, to produce the desired output (referred to as
information)
(b) Give one reason why a computer is referred to as an electronic device
- It uses electrical signals to process data
- It is made up of electronic components and uses electric energy to operate
2. Explain the following terms as used in computer science
(i) Data: A collection of raw facts, figures or instructions that do not have much meaning to the user
(ii) Program: A computer program is a set of related instructions which specify how data is to be
processed
A set of instructions used to guide a computer through a process
(iii) Data processing: It is the process of collecting all terms of data together & converting them into
information
(iv) Information: Data which has been refined summarized & manipulated in the way you want it, or into
a more meaningful form for decision- making
3. State any three functions of a computer
- Accepting data
- Processing the data
- Producing information
4. Explain the following input/ output terms as used in computer systems. Give an example for
each
(a) Read - To transfer data from an input device to the computer, e.g. the computer
reads data from a disk, a keyboard, etc
- To move or copy data from backing storage to the main Storage
(b) Write - To transfer information from the computer to an output
Device e.g. the computer writes output on a printer or onto a disk.
- To move or copy data from the main storage to a backing storage
5. State four different parts that make up a computer (2 mks)
- System unit
- Monitor
- Keyboard
- Mouse
- Printer
- Modem
- Scanner
- Speakers
- Graph plotters
6. (a) Explain the term system Unit
This is the casing that houses the internal components of the computer such as the CPU and
storage devices
(b) List four devices located under the cover of the system unit
- Central processing Unit (CPU)
- Motherboard
- Power supply unit
2
, - Main memory
- Hard disk
- Disk drives
- Battery
- Buses
- Input/ output ports
- Video card
- Expansion slots
(c) Give two differences between tower – style and desktop system units
- Tower style system unit is designed to stand alone or to be placed on the floor, desktop
units lie on the desk with the monitor placed on top
- Tower style units have more space for expansion than the typical desktop units (2 mks)
7. Computers have evolved through a number of generations. List any 4 characteristics of the
first generation of computers.
- Large in physical size
- Relied on thermionic valves (vacuum tubes) to process and store data
- Consumed a lot of power
- Produced a lot of heat
- The computers constantly broke down due to the excessive heat generated; hence were
short- lived, and were not very reliable
- Their internal memory capacity/ size was low
- Processing speed was very slow
- Very costly
- Used magnetic drum memory
8. Briefly explain the classification of computer according to historical development
(generations)
First generation computers
- Used vacuum tubes in their memory
- Large in physical size
- consumed a lot of power
- Produced a lot of heat
- The computers constantly broke down due to the excessive heat generated; hence were
short- lived and were not very reliable
- Their internal memory capacity/ size was low
- Slow in processing data
- Very costly
- Used magnetic drum memories
- Cards were sued to enter data into the computers
Second generation computers
- Used transistors in their memory
- They consumed less power & produced less heat than the first generation computers
- They were relatively faster than the 1st generation computers
- Used magnetic core memories
- Were less costly than first generation computers
- RAM memory capacity was 32 KB
Third Generation computers
- Used integrated circuits in their memory
- They were faster than second generation computers
- RAM memory capacity was 2 GB
- Slightly smaller in size than 1st & 2nd generation computers
- They used a wide range of peripheral devices
3
, - Could support remote communication facilities/ more than one user at the same time
- Magnetic disks were introduced for storage purposes
Fourth generation computers
- Used large scale integrated (LSI) circuits & very large scale integrated (VLSl) circuits in
their memory
- They were small & very fast
- Had storage (memory) capacity
- Magnetic disks, bubble memories & optical disks were used for storage
- The first operating system was introduced
Fifth generation computers
- Are the modern computers
- Are designed/ constructed using parallel architectures, 3 –D circuit design &
superconducting materials
- Are very powerful, with very high processing speeds
- The computers can perform multiprocessing
- Have virtually unlimited ( very high) memory sizes
- Can support complex programs
- Use advanced hard disks and optical disks for storage, e.g. DVDs
- Use of zip disks
- Use of multi user operating systems & advanced application programs
9. State four factors used to classify computers
- Physical size & processing power
- Power
- Functionality (mode/ method of operation)
- Type of processor (CPU)
10. State the differences between desktop computers and laptop computers
- Desktop is designed to be used when placed on a desk in an office environment. A
laptop can be used comfortably when placed on the User’s lap
- A laptop is small & portable; desktop computers are not portable
11. (a) Explain the emerging trends in microcomputer technology in relation to size
- PCs are becoming small and portable, e.g. personal Digital Assistant (PDA).
(b) Give two reasons why smaller computers like Laptops tend to be more expensive
than Desktop computers
- The technology of producing smaller devices is expensive
- They are convenient because they are portable
- They have advanced power management capabilities (they consume less power since a
laptop can operate on rechargeable batteries
12. Which category of computers would you place an N- series Nokia phone
- Microcomputer/ palmtop
13. Give three reasons why a mobile phone is regarded to be a computer
- It is electronic * uses electric energy to operate
- It has a display unit (screen)
- It has a keypad
- It has a memory for storage
- It is programmable
14. (a) Mention three Analogue devices
- Computer used to control a flight Simulator for training pilots
- Bathroom scale
- Thermometer
- Speedometer
- Post- office scale
4
FORM 1-4 2018
COMPUTER STUDIES
This booklet contains questions and answers from every topic from
form one to form four. The questions have been very well explained
and illustrated. Learners will find it easy to revise using this booklet.
Teachers can also use this booklet to set exams and prepare marking
schemes.
Buria Erick
, K.C.S.E TOPICAL REVISION SERIES 2018
COMPUTER STUDIES
INTRODUCTION TO COMPUTERS
1. (a) Clearly define a computer
- A computer is an electronic device that operates (works) under the control of programs stored
in its own memory unit
- An electronic device that accepts data, as input and transforms it under the influence of a set of
special instructions called programs, to produce the desired output (referred to as
information)
(b) Give one reason why a computer is referred to as an electronic device
- It uses electrical signals to process data
- It is made up of electronic components and uses electric energy to operate
2. Explain the following terms as used in computer science
(i) Data: A collection of raw facts, figures or instructions that do not have much meaning to the user
(ii) Program: A computer program is a set of related instructions which specify how data is to be
processed
A set of instructions used to guide a computer through a process
(iii) Data processing: It is the process of collecting all terms of data together & converting them into
information
(iv) Information: Data which has been refined summarized & manipulated in the way you want it, or into
a more meaningful form for decision- making
3. State any three functions of a computer
- Accepting data
- Processing the data
- Producing information
4. Explain the following input/ output terms as used in computer systems. Give an example for
each
(a) Read - To transfer data from an input device to the computer, e.g. the computer
reads data from a disk, a keyboard, etc
- To move or copy data from backing storage to the main Storage
(b) Write - To transfer information from the computer to an output
Device e.g. the computer writes output on a printer or onto a disk.
- To move or copy data from the main storage to a backing storage
5. State four different parts that make up a computer (2 mks)
- System unit
- Monitor
- Keyboard
- Mouse
- Printer
- Modem
- Scanner
- Speakers
- Graph plotters
6. (a) Explain the term system Unit
This is the casing that houses the internal components of the computer such as the CPU and
storage devices
(b) List four devices located under the cover of the system unit
- Central processing Unit (CPU)
- Motherboard
- Power supply unit
2
, - Main memory
- Hard disk
- Disk drives
- Battery
- Buses
- Input/ output ports
- Video card
- Expansion slots
(c) Give two differences between tower – style and desktop system units
- Tower style system unit is designed to stand alone or to be placed on the floor, desktop
units lie on the desk with the monitor placed on top
- Tower style units have more space for expansion than the typical desktop units (2 mks)
7. Computers have evolved through a number of generations. List any 4 characteristics of the
first generation of computers.
- Large in physical size
- Relied on thermionic valves (vacuum tubes) to process and store data
- Consumed a lot of power
- Produced a lot of heat
- The computers constantly broke down due to the excessive heat generated; hence were
short- lived, and were not very reliable
- Their internal memory capacity/ size was low
- Processing speed was very slow
- Very costly
- Used magnetic drum memory
8. Briefly explain the classification of computer according to historical development
(generations)
First generation computers
- Used vacuum tubes in their memory
- Large in physical size
- consumed a lot of power
- Produced a lot of heat
- The computers constantly broke down due to the excessive heat generated; hence were
short- lived and were not very reliable
- Their internal memory capacity/ size was low
- Slow in processing data
- Very costly
- Used magnetic drum memories
- Cards were sued to enter data into the computers
Second generation computers
- Used transistors in their memory
- They consumed less power & produced less heat than the first generation computers
- They were relatively faster than the 1st generation computers
- Used magnetic core memories
- Were less costly than first generation computers
- RAM memory capacity was 32 KB
Third Generation computers
- Used integrated circuits in their memory
- They were faster than second generation computers
- RAM memory capacity was 2 GB
- Slightly smaller in size than 1st & 2nd generation computers
- They used a wide range of peripheral devices
3
, - Could support remote communication facilities/ more than one user at the same time
- Magnetic disks were introduced for storage purposes
Fourth generation computers
- Used large scale integrated (LSI) circuits & very large scale integrated (VLSl) circuits in
their memory
- They were small & very fast
- Had storage (memory) capacity
- Magnetic disks, bubble memories & optical disks were used for storage
- The first operating system was introduced
Fifth generation computers
- Are the modern computers
- Are designed/ constructed using parallel architectures, 3 –D circuit design &
superconducting materials
- Are very powerful, with very high processing speeds
- The computers can perform multiprocessing
- Have virtually unlimited ( very high) memory sizes
- Can support complex programs
- Use advanced hard disks and optical disks for storage, e.g. DVDs
- Use of zip disks
- Use of multi user operating systems & advanced application programs
9. State four factors used to classify computers
- Physical size & processing power
- Power
- Functionality (mode/ method of operation)
- Type of processor (CPU)
10. State the differences between desktop computers and laptop computers
- Desktop is designed to be used when placed on a desk in an office environment. A
laptop can be used comfortably when placed on the User’s lap
- A laptop is small & portable; desktop computers are not portable
11. (a) Explain the emerging trends in microcomputer technology in relation to size
- PCs are becoming small and portable, e.g. personal Digital Assistant (PDA).
(b) Give two reasons why smaller computers like Laptops tend to be more expensive
than Desktop computers
- The technology of producing smaller devices is expensive
- They are convenient because they are portable
- They have advanced power management capabilities (they consume less power since a
laptop can operate on rechargeable batteries
12. Which category of computers would you place an N- series Nokia phone
- Microcomputer/ palmtop
13. Give three reasons why a mobile phone is regarded to be a computer
- It is electronic * uses electric energy to operate
- It has a display unit (screen)
- It has a keypad
- It has a memory for storage
- It is programmable
14. (a) Mention three Analogue devices
- Computer used to control a flight Simulator for training pilots
- Bathroom scale
- Thermometer
- Speedometer
- Post- office scale
4
