Sample exam questions and answers
Question 1
The CPU is one of the major parts of a computer system and it consists of two main
components.
a. List the TWO main components present in a CPU.
b. State TWO functions of EACH of the components identified in your answer to 1a.
Suggested answer
a. Control Unit and Arithmetic Logic Unit (ALU)
b. The functions of the Control unit:
 read and interpret input given
 control operations of CPU
The functions of the ALU:
 perform mathematical or arithmetical operations
 perform logical operations
Question 2
In a computer system there are primary storage and secondary storage.
a. State the difference between primary storage and secondary storage.
b. Give ONE example of a primary storage medium.
c. Give ONE example of a secondary storage medium.
d. State TWO advantages of secondary storage media over primary storage medium.
Suggested answer
a. Primary storage is storing data and programs that are currently being processed by the
CPU and secondary storage is storage of data for later use.
b. RAM
c. Hard disk, floppy disk, flash drive, magnetic tape
d. Advantages:
 Secondary storage has larger storage capacity than primary storage
 Secondary storage is cheaper than primary storage
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Question 3
A file has a size of 100KB.
a. How many characters could be stored in this file?
b. How many bits does it contain?
Suggested answer
a. 8 bits or 1 byte is required to form one character and 1 KB = 1024 bytes.
Therefore, the number of bytes in 100 KB would be:
1024 x 100 = 102400 Bytes which means a 100KB file would contain 102400
characters
b. 1 byte is 8 bits, so the number of bits that is present in 100 KB would be:
1024 x 100 x 8 = 819200 bits
Question 4
OMR is a popular input device commonly used by many examination boards.
a. What does OMR stand for?
b. Suggest ONE use of OMR by the examination boards.
c. Give ONE another application in which OMR is commonly used.
Suggested answer
a. OMR stands for Optical Mark Reader.
b. An OMR is commonly used by examination boards to mark multiple-choice
examination papers.
c. Another application in which an OMR is commonly used is to read numbers chosen by
persons on lottery slips.
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Question 5
Hard disks are one of the most popular secondary storage media. They can be fixed head
drive, movable head drive.
a. Fixed head drives are faster in accessing data than a movable head drive. Why?
b. As it relates to hard disk, what is meant by ‘cylinder’?
Suggested answer
a. Movable head drives have only one read/write head per surface of the disk. But in fixed
head drives each track of the disk has its own read/write head so it can locate and
retrieve information faster than movable head drive.
b. The tracks in a hard disk pack that share the same track number together form a
cylinder.
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Question 6
User interfaces are used to help the user interact with the computer system. Examples of
interfaces include command-driven, graphical user and menu-driven.
a. State the difference between a command-driven interface and a graphical user
interface.
b. State ONE main interface device for command-driven interfaces.
c. State ONE main interface device for menu-driven interfaces.
d. Menu-driven interfaces can use pull down or pop up menus.
i. State the difference between pull-down and pop-up menus.
ii. Give ONE example of a pull-down and a pop-up menu.
e. Would a command-driven or graphical user interface be more suitable for an expert
computer user? Why?
Suggested answer
a. In command-driven interfaces, commands or instructions with specific rules are
entered in order to perform a task; in a GUI, windows, menus, icons, pointers, etc are
commonly used to perform a task.
b. One main interface device for command-driven interfaces is the keyboard.
c. One main interface device for graphical user interfaces is the mouse.
d.
i.
A pull-down menu pulls down from the horizontal menu bar. A pop-up pops up
when you right click on something.
ii.


A pull down menu – the File menu of MS Word
A pop up menu – right clicking mouse button displays a pop-up menu
e. Command-driven interfaces would be most suitable for an expert user as they can
perform many tasks by entering a single command.
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Question 7
Printers can be classified into impact or non-impact.
a. State the different between impact and non-impact printers.
b. List TWO examples of impact printers.
c. List TWO examples of non-impact printers.
d. Give ONE application in which EACH of printers identified in your answers to questions
(b) and (c) can be used.
Suggested answer
a. An impact printer is where the printing mechanism makes a physical contact (impact)
with the paper, while a non-impact printer does not.
b. Impact printers: dot matrix, plotter
c. Non-impact printers: ink jet, laser
d.




Dot matrix: used for printing documents on continuous sheets of paper at a cheaper
rate
Plotter: used for printing architectural drawings
Ink jet – used for printing documents in a small office
Laser – used for printing documents in a large organisation
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Question 8
John decides to computerise his Pet store. He wants to purchase software that will allow
him to carry out his job much more easily and efficiently. The software vendor gave him
two choices: buy software off the shelf or have software made specifically for his
business.
a. What are the generic names for:
i. off-the-shelf software
ii. software made by a software company specifically for his business
b. List TWO advantages of off-the-shelf software.
c. Give ONE major advantage of software that is made specifically for John.
d. Give ONE disadvantage of EACH of the types of software mentioned.
Suggested answer
a.
i. general purpose software
ii. custom-written software
b. Advantages of general purpose software: it’s readily available and cheaper than
custom-written software
c. Advantage of custom-written software: it meets his specific requirements
d.


Disadvantage of general purpose software: it cannot be modified that easily
Disadvantage of custom-written software: it is very expensive to buy and difficult to
maintain.
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Question 9
Secondary storage devices can provide direct access or sequential access.
a. State the difference between direct access and sequential access.
b. Give one example of a device that provides sequential access.
c. Give one example of a device that provides direct access.
d. State one disadvantage of devices with sequential access only.
Suggested answer
a. Sequential (or serial) access is accessing information in the same order as it is
physically stored. The time taken to retrieve information is dependent on where it is
stored. Direct access is accessing information in any order. The time taken to retrieve
information is not dependent on where it is stored.
b. Magnetic tape
c. Hard disk, CD ROM
d. Devices with sequential access are slow in retrieving information.
Question 10
a. State the difference between the hexadecimal number system and the octal number
system.
b. Give ONE area in which the hexadecimal octal number system is commonly used in a
computer system.
c. List TWO ways in which integers can be represented.
d. Give the steps for converting an integer into Binary Coded Decimal form.
Suggested answer
a. The octal number system or base 8 number system uses eight digits (0, 1, 2, 3, 4, 5, 6
and 7). The hexadecimal number system or base 16 number system uses16 digits
(0,1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E and F).
b. When you have to deal with large values, binary numbers become difficult to manage
and the hexadecimal (base 16) numbering system makes it more compact.
c. Two ways in which integers can be represented are:
 sign and magnitude
 two’s complement
d.
Step 1: Convert each decimal digit into its binary.
Step 2: Add zeroes in front to make it four bits each.
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