Computer Studies Paper 1 Questions and Answers - Sukellemo Joint Mock Examinations July 2020

Instructions

Answer all the questions in section A
Answer question 16 and any other three in section B
All answer should be written in the spaces provided below each question
All answer should be in English

QUESTIONS

Section A (40 marks)
Answer all the questions in this section

State the type of memory found in printer and network interface card to help in smooth flow of data between the devices (1 mark)
State TWO effects of the following: (2 mark)
1. Low hanging bulbs in a computer lab.
2. Having taps and sinks in the computer lab.
List two examples of modifier keys on the computer keyboard. (2 marks)
For each of the following computer generations, identify the technology used to control internal computer operation (2 marks)
1. First Generation
2. Second generation
3. Third generation
4. Fourth generation
1. Explain the term plug and play as used in computing (2 marks)
2. State three tasks performed at the analysis stage during system development (3 marks)
Study the diagram below.
1. State the device used to read such document (1 mark)
2. Give reason the device mentioned in (a) above is suitable (1 mark)
A computer specification has the following details
- Modem
- Dual core
- 1.44 MB floppy disk drive
- 20 GB hard disk
- Full multimedia
- Pre-installed operating system
  1. What is meant by Dual core? (1 mark)
  2. What is the use of a modem (1 mark)
Define the following terms:
1. Resolution (1 mark)
2. Dot pitch (1 mark)
3. Display size (1 mark)
1. Explain the functions of the components of the task bar (3 marks)
2. Distinguish between software configuration and software installation (2 marks)
1. A student typed a letter in a word processor and the last line of the letter flowed to the second page. State three ways in which the student could have adjusted the letter to fit on one page without changing the paper size (3 marks)
2. List two number formats used in electronic spreadsheets (2 marks)
1. Mention two methods of data verification as used in data processing (2 marks)
2. List three differences between while.......do and repeat........until looping control structures (3 marks)
State two ways in which computer technology is used by the police in detecting crimes (2 marks)
Identify the personnel responsible for each of the following: (4 marks)
1. Ensuring up to date maintenance of ICT records
2. Identifying and fixing security loopholes
3. Managing the learning and examination processes
4. Testing and debugging programs

Section B (60 marks)
Answer question 16 and any other three questions from this section

1. A retailer has two categories of customers (Silver and Gold). Processing category Silver obtain 10% discount on all orders up to Ksh. 20,000. Otherwise the discount is 20% on entire order. Category "Gold' obtains 30% on all orders if the debt payment records is good otherwise the discount is 15%. Write a pseudo-code that would be used to display the discount on processing order. (5marks)
2. Draw a flowchart that will display the discount on processing order. (8 marks)
3. Define the following terms as used in programming (2marks)
  1. Assembler
  2. Compiler

A database has been setup to hold information about cars. Study the extract below:

Car ref	No of doors	Engine (litres)	CO₂ (g/km)	Fuel (km/litre)	No of Cylinders
A	3	1.4	145	15.3	4
B	4	2.0	193	12.3	4
C	5	2.5	231	10.9	6
D	3	2.0	190	11.2	6
E	4	1.3	120	17.5	4
F	5	1.8	180	14.6	6
G	4	3.0	240	9.5	4
H	4	1.2	115	19.7	3

Using car ref only, write down which cars would be output if the following search condition was used; (No of doors = 4) AND (fuel used (km/litre)>15) (2 marks)
Write down a search condition to find out which cars have engines larger than 1.8 liters OR have CO2 emissions higher than 150 g/km (2 marks)
The database is sorted in ascending order on fuel used (km/litre). Using car ref only, write down the results of the sort (2 marks )
Identify two characteristics of a good primary key in a database (2 marks)
Differentiate between append and update query as used in database (2 marks)
State the meaning of the following terms as used in the context of desktop publishing (3 marks)
Publications
Master page
Orphan
Thumb nail

1. state three communication services offered through the internet (3 marks)
2. List any THREE items that may be referred to as data terminal equipments in a network. (3 marks)
3. Briefly explain the following terms as used in networking. 4 marks)
  1. Remote communication
  2. Distributed processing
4. State THREE advantages and TWO disadvantages of mesh network topology. (5 marks)
  Advantages
  Disadvantages
1. an expert system is being developed to help engineers diagnose faults in aero engines. Explain three components of such an expert system (6marks)
2. Another method used to identify and rectify faults is to train engineers using virtual reality systems.
  1. Define the term virtual reality (2 marks)
  2. Identify three equipment used in virtual reality (3 marks)
3. Explain two ways in which the operating is used in memory management (4 marks)
1. two complements is the most popular way of representing negative numbers in computer systems. List two advantages of using this method. (2 marks)
2. Using two complements work out: -21₁₀ + 7₁₀(6 marks)
3. Convert the following number into their octal number format
  1. Determine the hexadecimal equivalent of 7468 (3 marks)

MARKING SCHEME

Section A (40 marks)
Answer all the questions in this section

State the type of memory found in printer and network interface card to help in smooth flow of data between the devices (1 mark)
- Buffer ---- 1 mark
State TWO effects of the following: (2 mark)
1. Low hanging bulbs in a computer lab.
  - They may affect the eyesight of the user due to reflections
  - They may cause fire accident if accidentally knocked
    Award 7 mark for any correct answer
2. Having taps and sinks in the computer lab.
  - Water from the taps may spill and this may cause slippery floors which may lead to accidents
  - Water from the taps increase humidity and causes rusting of computer parts Award 1 mark for any correct answer
List two examples of modifier keys on the computer keyboard. (2 marks)
- Control, Shift, Alt
  Award 1 mark each for any no correct answers
For each of the following computer generations, identify the technology used to control internal computer operation (2 marks)
1. First Generation_vacuum tubes / Thermionic valves
2. Second generation - Transistors
3. Third generation - Integrated circuits
4. Fourth generation- Large Scale integrated circuits/micro processors
1. Explain the term plug and play as used in computing (2 marks)
  - These are devices that are intended to work perfectly when first used or connected, without reconfiguration or adjustment by the user
2. State three tasks performed at the analysis stage during system development (3 marks)
  1. Problem definition
  2. Data collection
  3. Feasibility studies
  4. Proposal and evaluation of possible solutions
  5. Critical evaluation of the old system
    Award one mark each for any correct answer, maximum 3 points
1. State the device used to read such document (1 mark)
  - Magnetic Ink Character reader
2. Give reason the device mentioned in above is suitable (1 mark)
  - It reads characters written in magnetic ink such as in chegues
A computer specification has the following details
- Modem
- Dual core
- 1.44 MB floppy disk drive
- 20 GB hard disk
- Full multimedia
- Pre-installed operating system
1. What is meant by Dual core? (1 mark)
  - it's a type of computer processor made up of two processor integrated into one circuit
2. What is the use of a modem (1 mark)
  - The modem is used to connect the computer to the internet
3. Define the following terms:
  1. Resolution (1 mark)
    1. Resolution is the number of pixels (individual points of color) contained on a display monitor
    2. The sharpness of the image on a display depends on the resolution and the size of the monitor.
  2. Dot pitch
    1. It is the distance between individual pixels in a visual display device (1 mark)
  3. Display size (1 mark)
    1. It is the length of its diagonal, which is the distance from top right to bottom left, usually in inches.
1. Explain the functions of the components of the task bar (3 marks)
  - The Quick Launch bar-contains shortcuts to commonly used applications.
  - The Start Button--Opens the menu
  - The main Taskbar--displays icons for all open applications and files.
  - The System Tray--contains the clock and icons for some of the programs running in the background.
2. Distinguish between software configuration and software installation (2 marks)
  - Software configuration is the optimization which involves the choice of devices and settings that produce best possible software performance
  - Softwareinstallation is the setup of new software by copying of installable software files from the source to the computer ready for use.
1. A student typed a letter in a word processor and the last line of the letter flowed to the second page. State three ways in which the student could have adjusted the letter to fit on one page without changing the paper size (3 marks)
  1. Reduce spaces between sentences
  2. Reduce font size
  3. Remove spaces between paragraphs
2. List two number formats used in electronic spreadsheets (2 marks)
  - Currency, date, time, percentage, fractions, fraction, scientific

Mention two methods of data verification as used in data processing (2 marks)
1. Double entry
2. Manual reading

List three differences between while.......do and repeat........until loping control structures (3 marks)

While ....... do	R epeat....until
1. The condition is tested before the body is executed.	1. the condition is tested after the body is executed.
2. It is possible that the body may never be executed (this occurs . if the condition is true on the first test)	2. The body is always executed at least once
3. The loop is exited when the condition false.	3. The loop is exited is true when the condition is true.

State two ways in which computer technology is used by the police in detecting crimes (2 marks)
1. Drones: When police need an aerial view of a scene, drones can help law enforcement safely observe an area
2. Global Positioning Systems (GPS) for tracking of crimnals .
3. Surveillance cameras: Surveillance cameras can capture the events in a particular area and provide law enforcement with valuable insight
4. Voice analysis *
5. Use of street number plate scanning cameras to track movement of vehicles
Identify the personnel responsible for each of the following: (4 marks)
1. Ensuring up to date maintenance of ICT records
  Information system manager
2. Identifying and fixing security loopholes
  Data security analyst
3. Examining information system needs and problems system analyse
4. Testing and debugging programs
  Programmer

Section B (60 marks)
Answer question 16 and any other three questions from this section

1. A retailer has two categories of customers
  (Silver and Gold). Processing category
  Silver' obtain 10% discount on all orders up to Ksh. 20,000. Otherwise the discount is 20% on entire order. Category "Gold' obtains 30% on all orders if the debt payment records is good otherwise the discount is 15%.
  1. Write a pseudo-code that would be used to display the discount on processing order. (5marks)
    - Start
      Print" Enter customer category, order amount"
      Input: Silver, Gold, amount
      If Category - Silver and
      If order <= 20,000 then
      Discount = 10%
      Else
      Discount = 20%
      End if
      If Category = Gold and
      If Debt =good then
      Discount = 30%
      Else
      Discount = 15%
      End if
      End if
      Stop
2. Draw a flowchart that will display the discount on processing order. (8marks)
3. Define the following terms as used in programming (2marks)
  1. Assembler
    - This is a language processor that translates assembly language into machine readable forme
  2. Compiler
    - Its language processor that translates high level languages into machine language line by line
1. Using car ref only, write down which cars would be output if the following search condition was used: (2 marks) (No of doors= 4) AND (fuel used (km/litre)>15)
  Car ref=1
2. Write down a search condition to find out which cars have engines larger than 1.8 liters OR have CO, emissions higher than 150 g/km (2 marks)
  Engine litres > 1.8 AND CO, (g/km) 150
1. The database is sorted in ascending order on fuel used (km/litre). Using car ref only, write down the results of the sort (2 marks)
  G 9.5
  C 10.9
  D 11.2
  B 12.3
  F 14.6
  A 15.3
  E 17.5
  H 19.7
2. Identify two characteristics of a good primary key in a database (2 marks)
  1. Stable: does not change over time
  2. Minimal: fewest attributes necessary
  3. Definitiv: value always exists
  4. Accessibie: available when data created
  5. Unique: absolutely no duplicates
3. Differentiate between append and update query as used in database (2 marks)
  1. An Append Query is an action query (SQL statement) that adds records to a table.
  2. An Update Query is an action query (SQL statement) that changes a set of records according to criteria (search conditions) you specify.
4. State the meaning of the following terms as used in the context of desktop publishing (3 marks)
  1. Publications
    - It's a piece of creative work e.g. journal, book, card, magazine which is designed, formatted, and printed by use of a DTP software.
  2. Master page
    - The master page is a feature that enables you to define common structure and interface markup elements for your publication, including headers, footers, style definitions, or navigation bars
  3. Orphan
    - This is the first line of a paragraph that appears alone at the bottom of a page
  4. Thumb nail
    - A miniature representation of a page or image that is used to identify a file by its contents.
1. state three communication services offered through the internet (3 marks)
  1. Email and e-fax
  2. Instant messaging
  3. Video conferencing
  4. Tele/voice conferencing
2. List any THREE items that may be referred to as data terminal equipment in a network
  - Computers, printers, application servers, file servers, routers and bridges, dumb terminals