Download 1. Server and mainframes are types of computers used for

PCA0075
Revision Answers.
1. Server and mainframes are types of computers used for organizations. Provide three (3)
characteristics for each of these computers.
(6 marks)
1. SERVER
2. MAINFRAMES
 Make data and programs
 It is designed to handle and
available for network
process large amount of data in
users.
large organizations.
 It is not designed for
 Need to be placed in a special
individuals.
and secured room which has a
control climate.
 Allow user to access
network through
 It is powerful yet expensive.
client/server computing.
 Can be used by hundred of
thousand of people at the same
 Provide centralized
environment for the data
time.
and program to be
accessed by the user.
2. What is digital piracy? Give one (1) example to support your answer.
(2 marks)
Digital piracy is using unlicensed software or illegally sharing music or movies.
Example:
 Purchase single license software but installing it on more than one computer.
 Buy and duplicate the licensed software for distribution.
 Download and shared the music or video.
3. List five (5) basic functions of an operating system.
(5 marks)
The functions of the operating system are: Starting the computer
 Managing programs and applications
 Managing memory
 Handling messages from input and output devices
 Provide user interface for interaction with the computer
4. What is the difference between time bombs, worms and Trojan horse?
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(3 marks)
Time bombs
 Also called logic bombs
 Harmless until a certain event or circumstance activates the program
Worms
 Resemble a virus which spread from one computer to another
 Control infected computers
 Attack other networked computers
Trojan horses
 Disguise themselves as useful programs
 Contain hidden instructions
 May erase data or cause other damage
5. Backup software is used to copy data from a computer’s hard disk to another storage
medium. List and briefly explain two (2) types of backup.
(4 marks)
 Full backup– it will copy the entire hard disk’s content.
 Incremental backup– it will only copy files that have created or changed since
the last backup.
6. Explain the two (2) differences between ink-jet printers and dot-matrix printers.
(4 marks)
Ink-jet printer
-
-
-
Dot-matrix printer
Non-impact printer which print
-
Impact printer which print by
without physically touch the paper
striking a mechanism such as
Cannot print continuous form
printer hammer
paper
-
Can handle continuous form paper
Speed measured by number of
-
Speed measured by character per
pages per minute (ppm)
second (cps)
7. Illustrate all components needed for communication between two or more devices and label
each of them.
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(5 marks)
Communication
Device
Communication
Channel
Communication
Device
Receiving
Device
Sending
Device
8. Identify whether the phrases below are referring to hardware or software.
e.g.: The mouse is hardware
i.
ii.
iii.
iv.
v.
vi.
(5 marks)
Plotter :- ___________
Information on the display device :- ___________
Games that you download from the Internet :- ___________
A computer part that you can hold :- ___________
A QWERTY keyboard you use to input data :- ___________
A Facebook site : - ___________
9. Define the term network topology.
(1 mark)
Network topology is a physical layout of the devices in the network.
10. What will happen to the network if :(5 marks)
i.
ii.
iii.
iv.
v.




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more than one node send data at the same in the star network.
one of the nodes in ring network does not function.
hub in the star network does not function.
one of the nodes in bus network does not function.
one of the nodes in star network does not function.
collision occurs
entire network cannot function
entire network cannot function
network still operate normally
3

network still operate normally
11. What is data compression? Give two (2) compression techniques used to compress graphic
images and give example for each.
(5 marks)
 Is a technique of making file smaller for storing purposes.
 Lossy compression– JPEG
 Lossless compression– GIF
12. Briefly explain these terms:
i. Color depth
ii. Resolution
iii. Pixels
 Color depth – the number of bits devoted to each pixel.
 Resolution – density of a pixel usually describe as dots per inch.
 Pixels – tiny dots of white, black or color arranged in rows.
(3 marks)
13. What is a server? List two (2) characteristics of a server.
(6 marks)
Servers are computers that make program and data available to people who are
connected to a computer network. (2 marks)
(Any 2, 2 marks each)
1. Server can be as small as a microcomputer and as large as mainframe.
2. Not designed for individual use.
Typically centralized or operated from one location.
14. Define these terms:
i. Power On Self Test (POST)
(2 marks)
ii. (Basic input/output system) BIOS
(2 marks)
 POST - A series of test conducted to make sure that computer and associated
peripherals are operating correctly

BIOS – is the part of the system software that equips the computer with the
instructions needed to accept keyboard input and display information on screen.
15. What is a tailor-made application? Please list two (2) examples of tailor-made application.
(4 marks)
 Tailor-made applications are design for specialized fields of consumer market.

Example : Programs to handle billing needs of medical offices, to manage
restaurant, military, track occupational injuries.
16. What are the benefits of having licensed or legitimate software?
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(2 marks)



Entitled for certain warranties and guarantees.
To make sure that the software is bug-free.
Will have chance to upgrade to a new version.
17. Define these terms:
i. Cookies
(2 marks)
ii. Logic bomb
(2 marks)
 Cookies – are small files that are written to your computer’s hard disk by a website.
 Time bomb – is a virus that sits harmlessly on a system until a certain event or set of
circumstances causes the program to become active
18. Explain the difference between machine cycle with pipelining and machine cycle without
pipelining.
(4 marks)
Machine cycle with pipelining – CPU will execute the new instruction before the
previous instruction complete in the cycle.
Machine cycle without pipelining – CPU will wait until the first instruction complete
before start the second instructions.
19. Explain two (2) differences between memory and storage. Give one example each.
(5 marks)
Memory
-
Storage
Primary storage that store
-
instructions or data for a
instructions or data permanently
temporary period only
-
-
Non-volatile ; means instructions or
Volatile ; means instructions
data will remain in the storage even
or data will disappear when
though when the computer turn off
the computer turn off
-
Secondary storage that store
-
Example : Hard disk
Example : RAM
20. List and illustrate three types of LAN topologies.
(6 marks)
PC 2
PC 1
PC 2
PC 3
PC 1
Hub
PC 3
PC 4
PC 5
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PC 4
PC 1
PC 2
PC 3
PC 4
21. Explain the difference between wired and wireless transmission media. Give one example
each.
(5 marks)
Wired transmission media
Wireless transmission media
-
-
Connected through physical
-
Connected through the space or air
media
-
Example : microwaves
Example : twister pair cable
22. To ensure that data is accessible on demand, an organisation must manage and protect its
data. Thus, it is vital that the data has integrity and is kept secure. What is data integrity and
why is it important?
(2 marks)
 Data integrity identifies the quality of the data
 Garbage in, garbage out (GIGO) points out the accuracy of a computer’s output
depends on the accuracy of the input
23. To protect information on the Internet and networks, organisations and individuals use
variety of encryption techniques. How does encryption work, and list FOUR (4) simple
encryption algorithms?
(4 marks)
 Encryption prevents information theft and unauthorised access by converting
readable data into unreadable characters. To read the data, a recipient must
decrypt, or decipher, it into a readable form.
 Simple Encryption Algorithms: Transposition, Substitution, Expansion ,
Compaction
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