KNEC 2007 computer studies with marking scheme

Year of Examination:2007

Category: KCSE high school

Sub-category:Computer studies past papers and notes

Access level:free

1. Describe the computer booting process (2mks)

  • The internal power supply turns on and initializes.
  • The BIOS performs the power-on self test (POST). If there are any fatal errors, the boot process stops
  • The BIOS the looks for other devices’ ROMS to see if any of them have BIOSEs. Normally, the IDE/Ata hard disk BIOs will be found and executed. If any other device BIOSes are found, they are executed as well
  • The BIOS begins the search for a drive to boot from
  • Having identified its target boot drive, the BIOS looks for boot information to start the operating system boot process

2. State the functions of the following keys on the computer keyboard (2 mks)

c) Backspace – to delete a character to the left of the cursor

d) Insert (ins) – when the key is depressed editing is in overtype mode. Any

new text typed in the middle of a line is inserted between existing text while the existing text disappears/is deleted.

3. Jane has noticed the following problems in her computer:

  • It is taking longer time to start up;
  • It is often hanging
  • Applications are taking longer to load.

State three possible causes of these problems and how they can be solved (3mks)

a) Disk is fragmented – Defragment the disk by running the defragment utility. “

b) Virus/bug infection – run the antivirus utility

c) Capacity of RAM is small- Increase the size by replacing the existing chip with a higher capacity RAM chip.

d) Processor speed is low – Replace processor with a high speed processor.

4. a) Define authenticity as used in software selection (1 mark)

– This refers to the gem4ineness/originaUty/licensed software. Software that is not pirated.

b) List four ways of acquiring software in an organization (2 marks)

a) Buy Off-the-shelf package – This can be sold through retail outlets without any direct contact between the software developer and the customer.

b) Customized software applications – The software developer builds an application that meets the needs of the customer as defined in a specification.

c) Lease or Rent software.

d) Freeware/Shareware

5. Some of the storage disks available are: Zip disks, 31/2inch floppy disks, DVDs and 51/4 inch floppy disks. Arrange these devices in ascending order of storage capacity. (2 marks)

51/4 inch floppy disks, 31/2 inch floppy disks, Zip disks DVDs.

6. You have been asked to change your computer password. State a precaution you need to take in order to avoid each of the following:

a) Forgetting the password (1 mark)

– Compose password from a hintable phrase.

b) Hacking (1 mark)

– Use both alphabets and numerical in the password

7. State four benefits of using a computer in a school library (2 marks)

a) Record keeping made easier e.g. easy to track borrowers and books

b) Easy to search for library materials.

c) Books and other materials can be held electronically hence allowing multimedia usage.

d) Library materials can be electronically marked thus minimizing loses and theft.

8. Using six bits, find the two’s complement of -2310. (4 marks)


11÷2=5R1 2310=0101112

5÷2=2R1 Twos compliment = 101000

2÷2=1R0 + 1

1÷2=0R1 1010012

9. Explain data series, axis and legends as used in spreadsheet charts. (3 marks)

Data Series

The selected range in a worksheet that EXCEL converts into a graphic and displays as a chart (in spreadsheet applications)


A reference line from \which distances or angles are measured in a coordinate system, such as the X-axis and y-axis in the Cartesian coordinate system


Brief description accompanying an illustration (chart) also known as a caption

10. a) Describe the term data integrity. (2 marks)

The quality of correctness, completeness, wholeness, soundness and compliance with the intention of the creators of the data

b) State four situations in which data may lose integrity (2marks)

– Accidental insertion/alteration/modification/destruction

– Deliberate insertion/alteration/modification/destruction

– Transfer errors

– Lack of input validations

11. State the-function of each of the following:

a) Network interface card (1 mark)

– It provides connectivity between the PC and the network’s physical medium, the copper or fiber-optic cable.

-also handle important data-conversion function..

– supplies the basic addressing system that can be used to get data from one computer to another on the network

b) Network protocol (1 mark)

A common set of rules (usually defined by the International Standards body the IEEE) and signals (usually electrical, but may be laser light, infra red radio waves.) that computers connected to a network use in order to communicate on that network medium.

c) Hub (1 mark)

The hub or concentrator manages and controls all functions of the network It also acts as a repeater for the dataflow.

12. List four types of publications that can be designed by using desktop publishing software. (2 marks)

– Posters

– Banners

– Newsletters

– Cards

– Magazines

13. Differentiate between the following pair of terms as used in database design:

a) Input mask and design (2 marks)

An input mask often refers to a string expression that a developer defines which governs what is allowed to be entered into a typical edit/input box.

b) Table and query (2 marks)

Table – the basic unit of storing data in database

Query – a view created from table(s) that returns specific records based on a criterion.

14. List four factors to be considered when purchasing an operating system. (2 marks)

a) Does the operating system guarantee the security of your computer, the application software and the data you are handling?

b) The second crucial question, related with the issue of security, is the question of the type of network you work with. Is your computer a home computer for simple application such as word application or a corporate or business computer in which you handle high-tech data, confidential information and financial transactions which require high level security?

c) A third question you should answer when going for an operating system is the memory of your computer. Most current operating systems do not load onto less than 128MB of memory and therefore, for a computer with less memory, old school operating system such as DOS and windows 98 might suffice.

d) The cost


15. Write an algorithm to compute the area of triangle. (2marks) (Assume a right angled)

Read the length and height of triangle.

Calculate Area as 0.5 * length * height.

Output Area.


Answer question 16 and any other THREE questions from this section ill the spaces provide*

16. Study the flowchart below and answer the questions that follow

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i) Name the control structures used in the flowchart.

– Selection


ii) Determine the values of M, N, P and Q.



iii) Write the pseudo code for the flowchart



Initialize M=6, N=l 7 ELSE






b) List four functions of an assembler. (2 marks)

a) Translate assembly language to machine code.

b) Execute assembly language statements.

c) Create executable files (.exe) from the assembly language statements.

d) Allocate memory for machine code.

e) Debug for errors

17. a) Define the following web related terms:

i) Web browser (1 mark)

A browser is an application program that provides a way to look at and interact with all the information on the World Wide Web.

ii) Hyperlink (1 mark)

This is the clickable link in text or graphics on a Web page that takes you to another place on the same page, another page, or whole other site.

iii) Hypertext document (1 mark)

A document usually web document (file) where the user interacts with the whole document using hyperlinks

b) List six activities performed on the web (3 marks)

– Browsing for information

– Communication via email and chat groups

– Electronic commerce.

– Advertising of goods and services.

– Transfer of information thro’ FTP

c) An institution has ten stand alone computers.

i) Suggest with reasons the most appropriate topology required to inter-connect the computers. (3 marks)

a) Bus

Reason: Easy to set up, Low cost in terms of cabling QR

b) Star


Speed of data transmission is high, Easy to troubleshoot via central hub or switch

ii) State the necessary steps required to connect the computers to the Internet. (4 marks)

– Connect server to modem (router) and telephone/or use satellite dish/or radio

– Get an ISP to configure the Internet protocol

– Configure the rest of the computers to Internet access through a peer-to-peer configuration or a client-server configuration.

d) Below is an email address:

ggitau @moest.

Name the parts labeled:

  1. The local-part of the address/username
  2. host name domain-part
  3. generic (organizational) top level domain
  4. country code top level domain

18. A computer C directory has folders for Form 1, Form 2, Form 3 and Form 4. Each

class has student’s folders labeled according to their number. The students create their own folder for the are studying based on the table shown below.

a) Assuming there is one student per class, draw the corresponding directory

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Directory tree structure

c) i) A form four student wants to create a folder to store to project State the path for flat project folder. (2 marks) C:\FORM4\STUDNO\ADB\PROJECT

ii) Suggest how the student can ensure that: – work is not lost in case the hard disk fails. (1 marie)

– Keep backup copies of the project on offline secondary storage media.

– The project is not copied by other students. (1 mark)

– Use passwords for opening and modifying the project

d) Other than I/O devices, list other three devices under the control of the operating

– Main memory

– CPU/Processor

– Secondary storage

– Communication device

ii) Explain any one of the devices named in c(i) above. (1mrk)

e) Define the term trouble shooting

Systematic approach to locating the cause of a fault in an electronic circuit or system

19. A manager wishes to replace the ctirrent manual system with a computerized one

a) Describe three main areas that must be .evaluated to justify the replacement. (6 marks)

– Technical feasibility: Does’thecurrenttechnology (hardware & software)


– Economic feasibility: Are funds available?

– Social feasibility: How will the new system impact on the organization/society?

b) List the three areas that would be considered in the requirements specifications. (3 marks)

– Users specifications

– Software specifications

– Hardware Specifications

– Organizational integration specifications

c) State and explain three ways that can be followed to replace the current system. (6 marks)

– Running in parallel: New system runs along side the old one until the old one is discarded –

– Cut-over: New system replaces the old one instantly.

– Phased: New system is implemented in phases.

– Pilot sites: New system is tested on pilot sites then whole organization.

20. A head teacher keeps the following student details in a database: Name, Address, Town, Date of Birth, Marks scored, Fees paid.

i) Name the most appropriate primary key. Give a reason. (2 marks) Name

– Name alone is not unique though it is very rare that two or more students will share the same name.

ii) For each item in the student’s details above, indicate its most appropriate data type as used in the database. (3 marks)

Name Text

Address Text

Town Text

Date of Birth Date/Time

Mark Scored Numeric

Fees Paid Numeric/Currency

iii) a) Explain why input screens are better data entry designs than entering data directly to a table. (2 marks)

– Most forms are bound to one or more tables and query in the database hence a user can design input fields linked to several tables/queries.

– Forms are also appealing to the eye. They have GUI features unlike a table.

b) List two career opportunities associated with databases. (2 marks) Database Administrator

Data Administrator System Analyst

Database Developer

c) Distinguish between:

i) A table in word-processing application and a table in a database application. (2 marks)

– A table in a database application is a data entry/storage object, while a table in a word processor is made up of rows and columns of cells that one can fill with text and graphics. Tables in word processors are often used to organize and present information

– In a database one defines the data type for a table in design stage/view but not the case in a word processor.

ii) Mouse pointer and insertion point. (2 marks)

– Mouse pointer refers to an indicator on the screen, which responds to the movement of the mouse

– Insertion point is the place, in a full-screen editor or drawing program, where characters will appear if you start typing. The insertion point, which is different from the mouse pointer, looks like a thin vertical bar or, in some contexts, a tall, thin letter “I”; it is relocated by clicking at the desired position.

d) Outline the steps to be followed in order to merge cells in a word processing table. (2 marks)

i) Select/Highlight cells to be merged.

ii) Prom the menu bar clicks on table.

iii) Click on merge cells under the menu


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