COMPUTER STUDIES QUESTIONS AND ANSWERS MOD30042022001

COMPUTER STUDIES QUESTIONS AND ANSWERS

​​Section A: 40 Marks

Question Paper

1. ​State two hardware technological differences between the second generation and the third generation computers. (2 marks)

The 2nd generation use transistor in its logic circuit while the 3rd generation used integrated circuit

2. State two ways of ensuring proper ventilation in a computer room. (2 marks)

1. Having large windows
2. Having windows and vent area opened
3. Using air conditioning equipment
4. Providing spacious seating arrangement

3 (a) Explain the term toggle key as used in computer keyboard. (2 marks)

​These are keys that alternate the input mode. When pressed ON they are
intended to perform a task, when OFF, they perform different task. @ 2

​(b) List examples of toggle keys on a computer keyboard. (2 marks)

​Caps lock, Insert, Num Lock and Scroll lock.

4. ​State three factors to consider when selecting an operating system to install in a computer. (3 marks)

1. The hardware configuration of a computer such as processor speed, amount of memory and hard disk space available
2. The type of computer in terms of size and make
3. User friendliness of the operating
4. Number of users it can support
5. Number of processors and hardware it can support
6. Reliability and security provided by the OS.

5. ​Differentiate between analogue data and digital data as used in computers. (2 marks)

Analogue data

it is continous in nature

digital data

it is discrete in nature

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6. State two reasons for the increased use of laptop computers in government offices. (2 marks)

1. They are small and fit in a small storage space.
2. They are light weight hence can be carried to areas where their services are required.
3. The monitor, system unit, keyboard units are attached together hence making its use to be convenient.
4. Rechargeable / backup battery.
5. Generate less heat.

​​7. a) Explain three features of a graphical user interface as used in computers. (6 marks)

1. Programs are represented graphically by use of icons
2. Programs open by displaying windows
3. Commands are selected and issued using pointing devices e.g. mouse.
4. There is the use of pull down menus

​b) State the function of each of the following computer keyboard keys:

(i) Caps Lock (1 mark)
this is a toggle key that activates capital letter typing when on and small letters when off.
(ii) Shift (1 mark)
this is a key that when used with alphanumeric keys activates typing in uppercase and also enables keys with second functions to work. On its own, doesn't have a task to do.
(iii) Home (1 mark)
The home key takes the cursor to the start of a line when pressed. When used with the shift key, it takes the cursor to the start of a paragraph while using a text editor. When using a browser such as Firefox it scrolls the page to the top.​

8. State three measures that should be put in place in a computer laboratory to safeguard users’ health. (3 marks)

1. All power cables must be insulated and hidden from users.
2. The furniture used must be of standard computer furniture.
3. The room should be lit with adequate lighting.
4. The room must be ventilated.
5. Computer monitor should be fitted with antiglare to filter excess light rays emanating from the monitor.
6. Avoid slippery floors/cemented floors.
7. Controlling dust.

​9. State three ways in which barcode readers may be used in schools. (3 marks)

1. To take inventory of items in the school.
2. To keep track of employee login log out.
3. Used to transact business in the library.
4. Used to keep track of movement of goods.

​10. State three advantage of flat panel monitors over cathode ray tube monitors as used in computers. (3 marks)

1. They are compact and light weight;
2. They consume less power;
3. They do not suffer from geometrical distortions;
4. They do not cause eye fatigue.
5. They support many advanced technologies;
6. They can be made in almost any size and shape;
7. They support higher resolution.
8. Low heat radiation.

11. State three possible reasons for the extinction of daisy wheel printers in the market. (3 marks)

1. They supported one font size and font face;
2. They were monochrome printers;
3. They produced noise while printing;
4. They were very slow;
5. Did not print graphics.
6. Had poor print quality.

12. ​​A law firm prefers to use hard Copy output over soft Copy output when handling documents for legal matters. State two reasons for this preference (2 marks)

1. They are acceptable as exhibit in cases of litigation.
2. Can be used without a computer.
3. They are difficult to change without leaving any trace.
4. They can be used without power.
5. They can be used without the experience of computer usage.

​13. Describe two characteristics of parallel cables (2 Marks)

1. It is fast in transmitting data over short distances
2. Has high bandwidth because it has several conductors

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​Section B: 40 Marks: Answer any Four Questions

14. 

​​a) Define the operating system (1 mark)

An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is a vital component of the system software in a computer system. Application programs require an operating system to function.

​b) State any five functions of the operating system (5 marks)

1. Processor Scheduling
   The operating system allocates each job waiting for execution, processor time at each give interval. The OS schedules jobs according to priorities.
2. Resource allocation
   Each available resource is given a unique identification number called an interrupt request (IRQ). The OS uses the IRQ number to identify the resources being requested. Poor resource allocation would result to an undesirable condition referred to as deadlock. Deadlock is a situation which occurs when a process enters a waiting state because a resource requested by it is being held by another waiting process, which in turn is waiting for another resource.
3. Memory management
   The operating system determines which task remains can be held by the memory and which one can be suspended to the secondary storage devices , output and to the processor.
4. Input/output management
   The OS coordinates between various I/O (input/output) and other peripheral devices such as auxiliary storage devices, making sure that data is transmitted securely.
5. Communication control and management
   This involves management of various communication devices and providing an environment within which communication channels operate.
6. Error handling
   The OS has many ways of alerting the user of errors that may arise out of illegal operations, hardware or software failure. Most OS express what the error is, and where possible make suggestions on how to correct the error.
7. Process management
   all processes from start to shut down
   booting, open, save, install, copy, print
8. File management
   this involves naming of file and folders, locations, attributes (size, type, modified, protection, password etc.
9. Security management
   this involves Virus management, Alert messages, Dialogue boxes, Firewall, passwords/Access protection etc.
10. Interrupt handling
    An interrupt is a break from the normal sequential processing of instructions in a program. A critical request causes the processor to stop executing the current process to attend to it, before returning the control back to the process that was initially interrupted. 

​c) Write the following acronyms in full (3 marks)
i) IRQ

Interrupt Request Number

​ii) WIMP

Windows, Icons, Menus and Pointing devices

​iii) GUI

Graphical User Interface

​d) State six factors to consider when choosing an operating system (6 marks)

1. Basic computer design
2. Applications intended for the computer
3. Hardware configuration of the computer
4. User friendliness
5. Initial cost of the operating system
6. Availability in the market of the operating system
7. The number of users the operating system can support
8. Documentation available
9. Reliability and security measures provided by the operating system

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15.

​a) Define the term internet (1 mark)

Internet is a global networking of computers for the purpose of communications and resource sharing.

b) State four requirements needed for internet access (4 marks)

1. Data Terminal Equipment (DTE) used to process, host and transmit data.
2. Transmission media used to transmit data
3. Internet Service Provider used to offer services to internet users by providing internet connection lines.
4. Software used to facilitate access to the internet.

c) State any three services provided by the internet (3 marks)

1. Electronic mailing (Email) for communication
2. E-Chat for interactive communication
3. E-conferencing for interactive online meetings
4. E-commerce to sell and buy online
5. Resource sharing such internet servers and database
6. Research of information
7. E learning to teach and learn online
8. Freelancing to work and earn online
9. VOIP (voice over internet protocol) to call and communicate with voice online
10. Booking of Hotels and Airlines
11. To access government services through portals such as ecitizen. 

d) List four advantages of the internet (4 marks) ​

1. Services offered are quick
2. Access to information is enormous
3. Updates are done frequently
4. Offers convenience especially in booking airlines or hotels
5. It is easily accessible
6. It is cheap to get services because it brings services closer to people
7. Creates jobs
8. Offers storage of information in remote servers (cloud computing)
9. Business transactions are easier and efficient.
10. Most internet services are free.

e) State three precautions that your school can implement in order to restrict computer studies students from accessing inappropriate content on the internet (3 marks)

1. Block/filter inappropriate content
2. set limits on downloads
3. monitor what children access online
4. counsel children especially on social sites
5. supervise children

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16. ​a) Define the following terms as used with data security: (4 marks)

i) Confidentiality

information belonging to an organisation or government should not be accessed by or disclosed to unauthorized people

ii) Integrity

data should not be modified without the owner's permission

iii) Data Security

​this is the process of protecting data from unauthorized access and data corruption throughout its lifecycle.

iv) Computer virus

A computer virus is a program/code/application/set of instruction written by malicious people that installs itself in a computer without owner's permission and altering the normal functions of the computer or destroy files.

b) State any five symptoms of a computer infected with a virus (5 marks)

1. Frequent error messages
2. loss or change of data
3. system crash
4. programs loading slowly
5. Files refuse to open
6. some programs fail to open or fail to install
7. computer runs out of sufficient memory

c) Hacking is a computer crime associated with breaking into a computer system through cracking passwords to access information for purposes of financial gains or blackmail. Discuss any other three computer crimes. (6 marks)

1. Logic bombs
   destroy data in the computer
   
2. Trojans or Trojan horses
   A Trojan horse or Trojan is a type of malware that is often disguised as legitimate software. Trojans can be employed by cyber-thieves and hackers trying to gain access to users' systems. Users are typically tricked by some form of social engineering into loading and executing Trojans on their systems.
   
3. Worms
   A computer worm is a type of malware that spreads copies of itself from computer to computer. A worm can replicate itself without any human interaction, and it does not need to attach itself to a software program in order to cause damage.
   
4. Stealth Virus
   Stealth Virus. A stealth virus is complex malware that hides itself after infecting a computer.
   
5. Nonresident virus
   a type of computer virus that doesn't reside within a computer's RAM. Non-resident computer viruses can still be deployed within RAM, but they don't stay there.
   
6. File Infectors
    A file infector virus is a type of virus that typically attaches to executable code, such as computer games and word processors. Once the virus has infected a file, it can spread to other programs, and even into other networks that utilize the infected files and programs.
   
7. Polymorphic virus
   Polymorphic viruses are complex file infectors that can create modified versions of itself to avoid detection yet retain the same basic routines after every infection. To vary their physical file makeup during each infection, polymorphic viruses encrypt their codes and use different encryption keys every time.
   
8. Directory virus
   As the name indicates, a directory virus functions by infecting the directory of your computer. A directory is simply a larger file that contains information about other files and sub-directories within it
   
9. Macro Virus
   Macro viruses add their code to the macros associated with documents, spreadsheets and other data files.
   
10. Boot virus
    A boot sector virus is a type of virus that infects the boot sector of floppy disks or the Master Boot Record (MBR) of hard disks.
    
11. Overwrite Virus
    A computer overwrite virus is a form of self-replicating malware that deletes data as it spreads. 
    
12. Direct action virus
    A Direct Action Virus is one of the most common forms of malware and infects systems by attaching itself with .exe or .com files. ... File Infectors is the most common type of computer virus which attaches itself with .com and .exe files to infect computer devices.
    
13. Multipartite virus
    A multipartite virus is a computer virus that's able to attack both the boot sector and executable files of an infected computer. If you're familiar with cyber threats, you probably know that most computer viruses either attack the boot sector or executable files.
    
14. Resident Virus
    ​A type of malware that hides and stores itself within the computer's memory
    

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17.

​​a) What are input devices as used in computer systems? (1 mark)

These are devices that enter data into the computer

​b) State three instances with reason where the use of a scanners is given a higher priority than Keyboards as a method of data entry. (6 marks)

1. In supermarkets
   At the point of sale terminal (POS). OBR scanners read products faster, more accurate and efficiently compared to the keyboard
   
2. Offices where data entry is plenty.
   OCR scanner is used to convert images into text for processing 
   
3. In banks
   To process cheques and confirm the originality of banking documents
   
4. Marking of examinations
   OMR scanner is used to quicken marking processes

c) State any three factors to consider when selecting an input device. (3 marks)

1. Compatibility with the existing system
2. Cost of the device
3. The extra features in the device
4. The purpose of the device
5. The speed in which input of data is required
6. The nature of data to be captured.

First 4x1

​d) State the meaning of the following phrases as used with computer systems:   (2 marks)
i) ‘Plug and Play’

This is a feature with the operating system that lets the computer user use a device immediately it has been plugged. ​Meaning that the user does not have to manually install drivers for the device or even tell the computer that a new device has been added.

​ii) ‘GIGO’

Garbage in Garbage out is a common phrase which means that the result of an output is influenced by the input. I.e. it does not change its nature if there was an error in the input, you expect the same error in the output.

​e) List an input device appropriate for each of the following tasks: (3 marks)

i) A botanist researcher wants to upload a picture of a new plant species into her laptop;
 - OCR Scanner, Camera
ii) An engineer wants to upload her hard copy house plan into the computer;
 - OCR Scanner
iii) A musician wants to record his audio music into the computer;
​ - Microphone

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18.

​a) State one clear distinction between a power cable and interface cable (2 marks)

A power cable is designed to transport electric energy while an interface cable is used to transmit data.

​b) Differentiate between parallel and serial interface cables (3 marks)

Parallel Interface

1. Transmit data over short distances
2. Transmit many bits of data at the same time
3. They are fast in transmission
4. Have a set of many conductors

Serial Interface

1. Transmit data over long distances
2. Transmit one bit of a data at a time
3. They are slow in transmission
4. Have only one conductor

​c) USB cables are the most popular interfaces with small computers today.
i) Write in full what the acronym USB stands for; (1 mark)

USB stands for Universal Serial Bus

​ii) State three advantages of USB interface over PS/2 interface. (3 marks)

USB

1. They are fast in transmission 
2. It has the capability of "hot plugging" which is the ability for plugging and unplugging a device without powering down.
3. USB cables also carry power, so you don't need extra cables or transformers

PS/2

1. Slower in transmission
2. To plug and use, the user must restart the computer

​iii) State any two application areas of USB cables which makes them more popular than other cables. (2 marks)

1. Charging of microcomputers such as palmtops
2. Support almost all peripheral devices
3. Used as a data cable that transport data across small devices

​d) State four safety precautions that should be observed before setting up computer hardware installation and maintenance activity. (4 marks)

1. ​Disconnect all drives from power source before starting to work on them.
2. Do not work on peripheral device without the guidance of a teacher.
3. Never work alone because, you may need help incase of an emergency.
4. Discharge any static electricity that might build upon the hands by touching an earthen metallic object and then wearing an antistatic wrist member. This is because your body can hold as much as 200 volts of static charge that can damage sensitive components on the mother board.
5. Avoid touching metal conductors with wet hands. This may cause short circuiting thus damaging chipsets.
6. Don’t force a component to open/eject. There are laid procedures for every opening/ejection. Force can break or destroy a component makeup.

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