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Q&A-KCSE Computer Studies Paper 1

Outline any 2 Examples of wireless transmission media       (2marks)

  • Radio waves
  • Microwaves
  • Infrared waves
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State ways in which an OS secures a computer system

  • Access Controls: Authentication of users in order to access files
  • Performing regular patches of updates
  • creating secure accounts with required privileges
  • scrutinizes all incoming and outgoing packets of data through a firewall
  • encryption of data, during transmission
  • Log files to detect any breach
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In reference to word processing, define the following terms

Word wrap

Justification

Drop cap

Word wrap - Is a word processing feature in which a word that does not fit in the current line is automatically moved at the start of the next line

Justification - refers to aligning text on both left and right margins

Drop cap - Make the first character of a paragraph occupy more than one line below it

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State three features of a typical operating system

- (provides) user interface
input/output control
security
handling interrupts
spooling
memory management
processor management
utilities (e.g. copy, save, delete, re-name, etc.)
maintain user accounts
load/run software
error reporting/handling
multiprogramming
batch processing (JCL)/real time processing
multitasking/multiuser/multi-access
file management

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What is the difference between a logical file and a physical file?

  • A physical file contains the original data whereas a logical file does not contain any data
  • A physical file contains one record format while a logical file can contain up to 32 record formats
  • A physical file can exist without a logical file while a logical file cannot exist without a physical file
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A school opted to use direct changeover approach when installing a new system. Explain three challenges that the school may face as a result of this approach (KCSE 2019)

  • The users may not have gained enough confidence to run the new system
  • It may be very inconveniencing in case the new system fails or faces problems
  • The weaknesses of the old system may not be corrected or may still be transferred to the new system
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Explain one reason why a computer needs to be connected to a stable power source

System Stability: Computers require a consistent and stable power supply to function properly. Fluctuations or interruptions in the power source can cause various issues that can disrupt the computer's operation or lead to hardware damage.

a. Data Loss: Sudden power outages or voltage fluctuations can cause the computer to shut down abruptly, resulting in data loss if unsaved work is not properly stored. This can be particularly problematic when working on critical tasks or handling important files.

b. Hardware Damage: Power surges or inconsistent power supply can damage the computer's internal components, including the motherboard, CPU, memory, and storage devices. These damages can result in system instability, reduced performance, or even complete hardware failure.

c. Operating System Corruption: Abrupt power loss or inconsistent power supply can corrupt the operating system files, leading to system crashes, error messages, and instability. This may require system repairs or reinstallation of the operating system.

d. Component Lifespan: Inconsistent power supply can put unnecessary stress on computer components, shortening their lifespan. Frequent power fluctuations or surges can cause wear and tear on various parts, reducing their efficiency and overall longevity.

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Explain why a developer, who is good at both low-level and high-level programming, would normally use high-level languages when writing programs                                                                                    [4 marks]

  • High-level languages have built-in functions;
  • High-level languages have built-in libraries;
  •  High-level languages have more support/help;
  • High-level languages have structures (such as selection and iteration);
  • High-level languages can be less machine-dependent/more portable;
  • It (usually) requires fewer lines of code to be written;
  • It is (usually) quicker to develop code in high-level languages;
  • It is easier to find mistakes in code;
  • The code is easier to maintain//understand;
  • • It is easier to structure code in high-level languages;
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The Acme company stores data for a private scientific research group. It has recently upgraded its storage capacity and needs to dispose of its existing hard drives securely. Outline two methods for the secure disposal of the data on the hard drives.

Acme company needs to ensure that if they are reselling the drives they wipe the drive (this should be done regardless of the destruction of the drive) to the DoD standard.

  • Disassemble the drive by pulling it apart the drive so that the data would not be accessed
  • Destroy the metal disk either by drilling holes so it cannot be read
  •  Encrypt drives with passwords that are not accessible
  • Degaussing the hard drives
  • Use specialized overwriting software

This would ensure that any software cannot be used to locate files.

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A large comprehensive school has over 500 computers connected to their Local Area Network (LAN) with a connection to the Internet. (a) Describe, in detail, four disadvantages for the school of having a network of computers compared to stand alone computers

 A network manager may need to be employed  which might be expensive

Could be infected with a virus that could spread to all other computers

Security problems receive traffic from other networks

Hackers may gain access as the network only as secure as weakest point of entry to data and steal/destroy

 The server/switch could go down (main cable break) so all workstations on the network are affected

 Can be expensive to set up as Initial cost of servers, communication devices, switches, network software etc. 

 Substantial Initial disruption: drilling holes, fitting trunking, running cables between buildings etc… 

 Can have a slow response time  due to heavy network traffic so users cannot work as effectively

 Detecting network problems can be more difficult on a network i.e difficult to isolate

 Can be slow to log in to a network  As it slow to download software/check password

 Only limited storage space available on network while one has access to all hard disc drive on standalone computer

 Time and effort to set up users o Can just start a standalone and use computer

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The data before encryption is known as .................................................. text.
To scramble the data, an encryption .................................................., which is a type
of .................................................., is used.
The data after encryption is known as .................................................. text.
Encryption prevents the data from being .................................................. by a hacker

The data before encryption is known as .......plain.................. text.
To scramble the data, an encryption ......................key.........................., which is a type
of ...................key............................, is used.
The data after encryption is known as ....................cipher............................. text.
Encryption prevents the data from being ......................understood...................... by a hacker

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Explain one benefit to a user if the program is distributed as free software

  • The user can access the source code  so, they can tailor the software to their needs and they can fix any bugs in it
  • the source code could be studied for educational purposes
  • The user can redistribute the software/program  but this must be done under the same terms as the original software
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 Describe four features of the operating system when providing a graphical user interface on a personal computer. Give a suitable example of each feature.

Windows for example a word processing application and a spreadsheet
 
Menus, for example, allow the user to perform operations or run applications such as right-click to create a new folder  
 
Icons for example a picture of linked computers for networking
 
Pointers(mouse or touchscreen)  for example to select items/trigger events  
 
Shortcuts for example to frequently used applications for example having a shortcut to your mail client on your desktop
 
File navigation for example when searching the hard disc for a file/folder using a browser
 
copying / deleting / moving/sorting/naming/searching of files or folders for example copying of a file from the hard drive to a USB pen drive (File handling)
 
Desktop customisation for example changing the colours and background image
 
Copy and paste for example between applications e.g. copying a graph from a spreadsheet to a word processor
 
Error messages for example provide users with error/warning/help messages for example ‘printer out of paper’ 

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When an image is inserted in a DTP document is selected, handles on its placeholders appear.  State three uses of these handles

  • Used to resize the image
  • Used to rotate the image
  • Used to move the image
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State three types of optical disks

  • compact disks
  • DVDs
  • Blue Ray
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The introduction of a new system involves evaluation and maintenance once the system is
implemented.
Describe the evaluation and maintenance stage of the systems development life cycle (SDLC)
and provide one example of an activity undertaken in this stage.

  • Continually monitoring, evaluating and updating the system once it is operational. Activities include rectifying bugs, requesting changes, updating aspects, finding errors, maintaining code etc.
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State three advantages of  biometric authentication

  • Protection against Password-related Vulnerabilities: Traditional password-based authentication methods are vulnerable to various risks, such as weak passwords, password sharing, or password theft.
  • Stronger Access Control: Biometric readers add an additional layer of access control to laptops. Even if someone gains physical possession of the laptop, they would still need the authorized user's biometric data to unlock it and access the data. This helps prevent unauthorized individuals from accessing sensitive information stored on the laptop,
  • Audit Trail and Accountability: Biometric authentication systems often come with built-in logging and auditing capabilities. This means that each time someone accesses the laptop using their biometric data, it can be recorded and associated with a specific user. This creates an audit trail, allowing organizations to track and monitor access to laptops and establish accountability in case of any security incidents or breaches.
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An organisation that supplies audiobooks over the internet is moving into a new office building.
 (a) One reason for networking devices is to provide access to the internet.
  (i) Give two other reasons for connecting devices to networks.
 

  • Share peripherals/devices (e.g. printers, scanners)
  • Communicate (e.g. email, instant messaging, play games)
  • Share data (e.g. files/music/videos/backups on servers)
  • Deploy/update applications
     
     

State the types of storage devices used in a computer

  1. Primary Storage (Memory):

    • Random Access Memory (RAM): This is a volatile memory used to store data and instructions that the CPU (Central Processing Unit) can access quickly. RAM is essential for running applications and the operating system. However, its contents are lost when the computer is powered off.
    • Read-Only Memory (ROM): ROM is a non-volatile memory that stores essential firmware and instructions necessary for the computer's boot-up process. It retains its contents even when the power is turned off.
    • Cache Memory: Cache is a small and fast memory located closer to the CPU. It stores frequently accessed data to speed up the processing.
  2. Secondary Storage (Mass Storage):

    • Hard Disk Drive (HDD): HDDs use magnetic storage to store data on rotating platters. They provide relatively large storage capacities and are commonly used in computers and laptops for long-term data storage.
    • Solid-State Drive (SSD): SSDs use NAND flash memory to store data, offering faster read and write speeds than HDDs. They are more durable and consume less power, making them increasingly popular in modern computers.
    • Optical Discs: CDs, DVDs, and Blu-ray discs are examples of optical storage media. They are mainly used for distribution of software, music, movies, and archival purposes.
    • USB Flash Drives: Also known as thumb drives or pen drives, these portable storage devices use flash memory to store data and can be easily connected to a computer's USB port.
    • Memory Cards: Memory cards, such as SD cards and microSD cards, are used in various devices like cameras, smartphones, and tablets to store data, photos, videos, etc.
    • External Hard Drives: These are HDDs or SSDs contained within an external enclosure, allowing users to expand their computer's storage capacity or create backups.
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(a) Name two pieces of hardware needed to enable video-conferencing to take place using a standard computer system.

(b) State one piece of specialist software needed to carry out video-conferencing.

(a)

webcam
speakers
microphone
broadband modem

(b)

use of CODEC (converts/compresses analogue data into digital data)
echo cancellation s/ware (allows talking in real time/keeps everything in sync)
compression s/ware for video/audio
s/ware to access broadband/networking

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