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Q&A-KCSE Computer Studies Paper 1

Give two different scenarios when a fast broadband connection is essential.

– when transferring large files/attachments with emails
– when streaming music/video files/bit streaming
– when using VoIP/video conferencing
– software updates
– online transactions
– Using VLE (Virtual Learning Environment)

Define patch as used in the operating system

Refers to a small piece of software designed to update, fix, or improve a specific part of the operating system or an application.

NB: Patches are typically released by the software's developer or the operating system vendor to address security vulnerabilities, software bugs, or to add new features or enhancements

Describe what is meant by ‘RAID 10’.

  • RAID 10 is a combination of RAID 0 (zero) and RAID 1 (one)

State the function of a switch in a computer network

  • It transfers data signals from one node directly to another in the network without broadcasting

Factors to consider when choosing DTP software. (4 marks)

  1. Availability in the market
  2. Initial and maintenance cost
  3. User friendliness
  4. Compatibility
  5. User needs

Explain, with examples where appropriate, the following five computer terms.

(a) Buffer

(b)batch processing

(c) e-commerce

(d) simulation

(a) Buffer

  • temporary storage or memory which compensates for the difference speed of peripherals and the CPU

(b)batch processing

  • processing doesn’t start until all data is collected
  • JCL (any reference to Job Control Language)
  • no need for user interaction
  • processed all in one go
  • done at “quiet” times
  • e.g. billing, payroll, cheque processing

(c) e-commerce

  • electronic commerce
  • buying and selling products/services using the internet/computer networks

(d) simulation

  • studying the behaviour of a system by using a model/mathematical representation
  • results can be predicted
  • e.g. flight (or other) simulator, modelling hazardous chemical process

(e) Email

  • sending messages from one device to another using computer networks/Internet

State what is meant by Computer Aided Design (CAD).

Give three different applications that make use of CAD.

Name three specialist input/output devices used in CAD.

software that can be used to design new products/amend existing products
makes use of features such as 2D, 3D, wire frames, library of parts, links to CAM

Give three different applications that make use of CAD.

aerospace
architecture
designing cars
designing consumer goods
chemical/nuclear plant design
designing electronic circuit boards
ergonomic design
landscape/garden design

Name three specialist input/output devices used in CAD.

large monitor/screen with hi-res
touch screen
plotter
space mouse/space ball/4D device
3D glasses (in some applications)
light pen
graphics tablet
3D printer
3D scanner

Explain why a firewall improves network security.

  • It prevents unauthorised access into the network (by checking IP/MAC address/packet content);
  •  It prevents unauthorised transmissions from inside the network to external locations;
  •  It monitors network traffic;
  • It makes sure that only the right/authorised traffic is allowed;
  • It opens/closes ports as necessary;

Briefly describe the following

Multitasking - the  capability of an operating system to enable users to run two or more programs at once on a single computer

Real time processing - data processing system in which the time interval required to process and respond to inputs is so small that the response itself is useful for controlling the physical activity of a process

Time-sharing processing  - a processing mode in which the central processor serves two or more users with different processing requirements (tasks)

On-line processing - is that type of processing where the result of data processing transaction is available immediately

Peter has installed internet on his home computer in order to use it for browsing. State three ways in which he would prevent viruses from infecting his computer.                                                        (3 marks)

  • Installing the latest versions of antivirus software
  • Avoiding downloads from untrusted sites
  • Scanning removable storage media for viruses before use
  • Scanning attachments for viruses before opening or downloading

Give four features of a Data Protection Act

  • data must be up to date
  •  data can only be read/used for the purpose for which it was collected
  • data must be adequate, relevant and not excessive
  • data must be accurate
  • data must be destroyed when no longer needed/don’t keep longer than necessary
  • data user must register what data stored
  • data must be used/collected fairly and lawfully
  • data must be held securely
  • data must be protected from accidental damage
  • only authorised personnel can have access to the data
  • fines are imposed for data mis-use
  • data should not be passed on to a third party without permission
  • a person can view data and have it changed/removed if incorrect

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)

Describe how the denial of service strategy works to compromise the security of networks.

  • A denial of service strategy usually works flooding the target host or network with traffic until the target can’t respond or crashes. The targeted systems operations are affected when users are unable to access information systems and or network services

State the functions of the following utility programs

(a) Defragmentation software

(b) Disk contents analysis/repair software

(c) Disk formatter

(a) Defragmentation software   -   Reorganises files on a disk to improve efficiency

(b) Disk contents analysis/repair software - Scans a hard disk to identify bad sectors

(c) Disk formatter -  Prepares a hard disk for first use

State the functions of the following registers

Program counter // PC
Stores the address of the next instruction to be fetched
Memory address register // MAR
Stores the address where data/instruction is to be read from or saved to
Memory data register // MDR
Stores data that is about to be written to memory // Stores data that has just been read from memory
Current instruction register // CIR
Stores the instruction that is currently being decoded/executed

Describe what is meant by shareware.

 the trial version of software for a limited time/number of uses with limited features  free of charge

If a full version is required need to pay a fee/sign up

When the trial is over user is asked to pay/sign up

Protected by copyright

Type of software licence
 

List four input devices used to capture data by way of scanning                 

Optical Mark Recognition; Optical Character Recognition; Magnetic Ink Character Recognition ; Optical Bar Recognition

Giving answers as readers is also acceptable, that is, Optical Character Readers, Magnetic Ink Character Readers; Optical Mark Readers

 

Outline one advantage and one disadvantage of interviews and questionnaires as data gathering techniques.
 

Interviews

Advantages

  • can gather specific information and additional information
  • high response rate to questions
  • The question can be rephrased to seek more clarification
  • it is possible to win the confidence of the interviewee and get honest answers

Disadvantages

  • time consuming
  • responses to interview questions are subjective.
  • the interviewee may not open up on some sensitive issues
  •  

Questionnaire

Advantages

  • easy to administer
  • can be anonymous.

Disadvantages

  • fixed (inflexible) design
  • potential differences in understanding and interpretation.

Give two uses of spreadsheets in a government office concerned with carrying out national census

Tallying population size Establishing demographic trends Drawing pie charts to show population share by gender Doing census budgets

Describe and give an example of one syntax and one logical programming error.

Syntax
An error that occurs when a command does not follow the expected syntax of the language, e.g. when a keyword is incorrectly spelt
Incorrect: IF A ADN B Then
Correct: IF A AND B Then

Logical
An error that causes a program to output an incorrect answer (that does not necessarily crash the program)
An algorithm that calculates a person’s age from their date of birth, but ends up giving negative numbers