2018 Computer Studies – Paper1
1. Reasons for the preference for laptops.
- They are small and fit in a small storage space.
- They are light weight hence can be carried to areas where their services are required.
- The monitor, system unit, keyboard units are attached together hence making its use to be convenient.
- Rechargeable / backup battery. Any 2 x 12. Reasons for the use of command — line interface OS
- They do not take up a lot of memory hence boot faster than the GUI OS.
- They have direct access or most hardware devices.
- They are cheaper to acquire as some can be downloaded free of charge. They can run on lower —bit hardware systems such as 32-bit computers. Any 3 x 13. Measures to be put in place in the laboratory to safeguard user health.
- All power cables must be insulated and hidden from users.
- The furniture used must be of standard computer furniture.
- The room should be lit with adequate lighting.
- The room must be ventilated.
- Computer monitor should be fitted with antiglare to filter excess light rays emanating from the monitor.
- Avoid slippery floors/cemented floors.
- Controlling dust.4. Ways in which barcode readers can be used in a school.
- To take inventory of items in the school.
- To keep track of employee login log out.
- Used to transact business in the library.
- Used to keep track of movement of goods.5. Advantages of flat panel monitors.
- They are compact and light weight;
- They consume less power;
- They do not suffer from geometrical distortions;
- They do not cause eye fatigue.
- They support many advanced technologies;
- They can be made in almost any size and shape; They support higher resolution.
- Low heat radiation.6. Reasons why daisy wheel printer are in extinct.
- They supported one font size and font face;
- They were monochrome printers;
- They produced noise while printing;
- They were very slow;
- Did not print graphics.
- Had poor print quality.7. Ways in which an OS secures computer system:
- Access controls: Authentication of users in order to access files;
- Performing regular patches of updates;
- Creating secure accounts with required privileges;
- Scrutinizing all incoming and outgoing packets of data through a firewall;
- Encryption of data, during the transmission stage; Password / biometric analysis;
- Log files to detect any breach. Any 3 x 18. Advantages of hardcopy output.
- – They are acceptable as exhibit in cases of litigation.
- Can be used without a computer.
- They are difficult to change without leaving any trace.
- They can be used without power.
- They can be used without the experience of computer usage. Any 2 x 19. (i) Thesaurus:
It is a feature in a word processor that suggest words with similar or opposite meaning to the selected word @l.
(ii) Comments:
It is a feature in WP that allows a user to attach a remark about the selection @l.
10. Multilevel list:
It is a format style that shows the listed items of different levels rather than one at one level.
Each level has different indentation and numbering style @2.
Example (Accept any)
1. Chapter One
Introduction
Definition of terms @l.
11. Distinction between real-time and distributed OS.
- Real-time OS reads information from input devices and must respond within a short duration of time to ensure correct performance.
- Distributed OS distributes computation among several physical processors which do not share memory or clock.12. Function of protect sheet:
- It is a feature used to prevent unwanted changes to be made on the data contained in a sheet by limit the ability to make changes.13. Computer based careers created by introducing computerized data processing.
- System analysts Hardware technicians
- Data entry clerks
- Programmers Networks techniciansDatabase administrators
- Web designers
- Network administrator14. = If (A1 > 10, Al * 77, Al * 50)
Compares the value in cell Al If it is greater than 10, if comparison is True, the results of operations Al * 77 is displayed, if it is False the results of the operations Al * 50 is displayed.
15. (a) Identifying technologies that could be used in the system.
— System ana1ysis/ information gathering/problem recognition (@ 1)
(b) Identifying the shortcoming of the old system
— Problem definition
(@ 1)
(c) Prepares the software migration plan
— Implementation stage (@ 1) 3
Section B (60 Marks) Marking Scheme
16. (a) Looping is the control structure that allows a block of code/statements to be repeated until a certain condition is fulfilled. @ 2 marks
- Accept any type of looping control structure
- (c) Distinction between a source program and compiler
- Source program is the original computer based instructions written by a programmer in a programming language whileA compiler is a program that processes statements/instructions and translates them into machine language.
17. (a) (i) Search-engine
It is a web-based application used to locate for an item or information from world wide web.
(ii) Factors that affects duration of download
- The size of the video
- The band width of the media used
- Availability of network
- Other activities that may be running in the computer.
- Other restrictions enforced in the computer
- The restrictions by the ISP
- Speed of computer (Any 3 @ l)(b) Causes of Wakulima system’s failure
- Lack of power supply to the system servers.
- Network infrastructure breakdown/poor network coverage/lack of connection.
- Program failure in the system/malware (virus).
- Hardware failure in the system.
- Human action which could be accidental or intentional.
- Lack of access rights.
- System overload (Any 4 @ 1 mark)(c) (i) Cropping
Used when handling a graphic and there is a need to remove some of the portions in the graphic.
(ii) Transparency
Used when there is a need to make the background of a graphic to be visible.
(d) Areas where infra-red radio waves are used.
- TV remote control communication; DVD remote control communication
- Communication between peripheral devices and the computer
- Data link over short distance using mobile phones Radio remote control
- Remote locking / opening doors/devices18. (a) Activities at the planning stages
- Identify opportunity for the new project.
- Analyse feasibility to establish the viability of the project.
- Develop a work plan.
- Identify appropriate staff to work in the project.
- Control and direct the project.(b) (i) Technical Feasibility
Meant to determine whether the proposed solution is technically practical/establish whether the technology is available /expertise is available. (@ 2)
(ii) Economic Feasibility
Meant to establish whether the proposed system will be cost effective. (@ 2)
(iii) Schedule Feasibility
Meant to establish whether the system can be implemented within an acceptable time kame. (@ 2)
(c) (i) Primary keys in the table Table 1 : Dept code @
Table 2 : Student’s Registration No. @
(ii) Benefits of referential integrity in the table
- No record can be added to the table 2 if its corresponding record in Table 1 does not exist.
- No record in Table 1 can be deleted without first deleting associated records in Table 2.
- Reduces data redundancies.
- Prevent deletion of related tables. (Any 2 x 2)19. (a) (i) Preserve check
It is a measure placed used to ensure that data item is in its original status. (@ 2 marks)
(ii) Data type check
It is a measure that ensures that correct data type is entered for each field. (@ 2 marks)
(iii) Check digit
This is a number calculated by the computer to make sure that the other numbers in a sequence have been entered properly. (@ 2 marks)
(b) (i) BCD
Binary Coded Decimal
(o i)
(ii) EBCDIC
Extended Binary Coded Decimal Interchange Code.
(iii) ASCII
American Standard Code for Information Interchange
- 20. (a) (i) I. Router It is the device meant to forward data packets between computer network in the school and the internet. (@ 2 marks)
H. Firewall
It is a device that prevents unauthorized access to or from a private network (school’s LAN) (@ 2 marks)
III. File server
It is a computer attached to a network whose purpose is to provide location for shared disk access (shared storage of computer files). (@ 2 marks)
(ii) Software to be installed in a computer
- Network operating system
- Browser/Mozi11a,firefox Necessary system drivers to supports installed hardware
- Protocols(SMTP,HTTP) (Any 2 @ 1 mark)(b) Use of computers in research for data management
- Used for data manipulation;
- Computers aid in data capturing;
- Computers can be used to store researched and analysed data;
- Information in computers can be a secondary source of data;
- Computers can be used to generate reports;
- Computers can be used to communicate researched work. (Any 4 x 1)(c) Advantages of online application services and shared processing resources.
Users will not be required to have powerful processing devices;
- Users can access the services from anywhere in the world;
- Users can access services at any time (24/7);
- Users can offload their data to the cloud infrastructure;
- Users can collaborate with remote users to process the data;
- The approach will cut out high cost of hardware;
- Sharing of resources;
- Faster access to service;
- Cost effective;
- Orders are made without going to the shop. (Any 3 x 1)
