Paper 1

(Theory)

Oct. Nov 2006

2 ½ Hours

MARKING SCHEME

Section a (40 marks)

1. What is meant by:

(a) Analogue data: Data that is based on physical variations such as loudness and pitch, electoral voltages etc

(b) Digital Data- Data, which use the computer’s binary number systems 0 and 1

2. Distinguish between transcription and transportation types of errors and give an example of each

– A transcription error is a specific type of data entry error that is commonly made by human operators or by optical character recognition (OCR) programs

E.g. Name: Stamley (wrong) instead of Stanley (Correct)

– A transposition error is an error caused by reversing two or more digits of an amount while posting transactions. These are almost always human in origin

An Example is ZIP code: 57429 (wrong) instead of 54729 (correct)

3. (a) What are peripheral devices? (1mks)

– Any device connected externally to the CPU

(b) Give two examples of peripheral devices (1mk)

– Mouse, Monitor, Keyboard, printer etc

4. (a) What is meant by the term user – friendly as used in software development?

– Software that is easier to use or work with (1mk)

(b) Distinguish between the terms single- tasking and multi- user as used in operating systems (1mks)

Single tasking – the O/S allows one program to be processed at a time

Multi – user an O/S that allows several tasks/ programs to be simultaneously

5. What actions should be taken in case of a fire outbreak in the computer laboratory? (4mks)

– Switch off main electrical supply

– Vacate the room

– Inform master in charge

– Call for help

– Try to extinguish using the appropriate fire extinguisher (not water)

6. (a) What is an internet service provider?

– A company that provides internet services. Connects users to the internet

(b) An employee in a business company is charged with the responsibility of putting the company advertisement on the internet

(i) State the professional title of the employee (1 mk)

– Web administrator, web designer

(ii) Give an example of software used by this employee to carry out the above task (1 mk)

  • HTML, Dream weaver, MS Front Page

7. Differentiate between COM ports and LTP ports

– COM port also known as a serial port transmits data bit by bit

– LTP port also known as a parallel port transmits multiple bits

simultaneously at a time.

8. Explain two ways in which ICT can enhance commerce

– Through better advertisement on the internet

– Through better services in retail shops via point of sale terminals

– Through electronic funds transfer

9. Explain the following software terms

(a) Portability (1mk)

– Ability of a software to work/ function in several computer hardware

and O/S platforms (

(b) Modularity

– Ability of software to be broken down into several sections for easier understanding and maintenance.

10. (a) State two applications areas of desktop publishing software. (2mks)

– Posters

– Book publishing

– Card design

 

(b) Explain the following graphic terms

– Rotate- to turn an image through an angle (1mk)

– Crop – to trim the edges of an angle (1mk)

11. Distinguish between margins and borders as used in word processing

(2mks)

A border is a decorative frame that surrounds a page or elements on a page. The border can be a simple rule line or an elaborate set of lines and curves. A border can be composed of repeating graphic elements. Borders can be used to set apart, draw attention or unify disparate elements.

Margin The blank space that surrounds the text on a page or the boundary line or the area immediately inside the boundary or the blank space that surrounds the text on a page.

12. (a) List two arithmetic operations that can be performed on a row of numeric data in a word processing table

+,-,x,/

 

b) In each case of (a) above, write the expression used (2mks)

= Function name (left) or = function name (right) e.g. = sum (left) (2mks)

13. List two methods of gathering information during system developments process. (2mks)

– Observations – Interviews

– Automatic data capture – Studying reports

14. Name three types of optical disks ( 3 mks)

– CD- ROM

– CD- RW

– CD- R

– CD – W

15. The diagram below shows a formatted plate surface of a storage disk

Pg106_0

 

Shade and label:

    1. One sector ( 1 mk)
    2. One block ( 1 mk)

SECTION B (60 MARKS)

16. (a) List two examples of: ( 2mks)

(i) Third generation languages

Pascal, basic, c

(ii) Object oriented languages (2mks)

VB, Small talk, C++

(b) Draw a flowchart to compare three non- equal numeric values A,B,C and print the largest of the three ( 1mk)

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17. (a) One of the functions of an operating system is job scheduling.

Explain what is meant by job- scheduling (1mks)

– Running of a particular job/ task under a system of priority, computer resource availability, time allocated to user etc.

(b) List and explain three types of user interfaces

– Command driven- Command language dialogues are those in which the user types instructions to the computer in a formally defined language

– Menu driven- These allow the user to issue commands by selecting choices from a menu of displayed alternatives

– Graphical User interface- These are those in which the user manipulates, though button pushes and movements of pointing devise such as a house, a graphic or iconic representation of the underlying data.

(c) Describe the following categories of software

(i) Firmware

– Soft ware that is burnt in computer ROM chips, usually system software

(ii) Proprietary Software

  • Any software as opposed to freeware, which is available freely

(d) A new company XYZ intends to go into the business of desktop publishing. Advise the company on three computer hardware system specification features to consider as a measure of enhancing performance. (1mks)

– Consider RAM capacity

– Consider speed of computer

– Consider hard disk capacity

18. (a) Distinguish between the following sets of terms as used in

spreadsheets

(i) Worksheet and workbook

Worksheet – The working area in an electronic spreadsheet on which a

user enters the spreadsheet data.

Workbook – A spreadsheet file. A workbook can obtain several worksheets

(ii) Filtering and sorting

Data filtering is a way of organizing spreadsheet data for ease of analysis. Often spreadsheet filters are used to “hide” rows of data that do not meet certain specified criteria. This allows you to analyze (e.g. count, observe etc) only certain “Filtering” groups of data.

Data sorting: Is a way of arranging record according to one of the fields in either ascending or descending order.

(b) State one way in which a user may reverse the last action taken in a spreadsheet package (1 mks)

– Use the undo command (ctrl + z)

(c) The following is a sample of a payroll. The worksheet row and column headings are marked 1, 2, 3, and A, B, C respectively

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Use the following expressions to answer the questions that follow

  • Basic pay- Hours worked x pay per hour
  • Allowances are allowed at 10% of basic pay
  • Gross pay- Basic pay + allowances
  • Tax deductions are calculated at 20% of gross pay
  • Net pay-= gross pay – tax deductions

Write formulae using cell references for the following cells

  1. D2 = B2 * C2
  2. E4 = 10% * D4 or 10% * (B4 * C4)
  3. F10 = D10 + E10
  4. G7 = 20% * F7
  5. H5 = H5 – G5

(d) (i) State three ways of moving round the page in desktop publishing window

(3 mks)

– Use cursor keys

– use mouse scroller

– Use scroll buttons (horizontal and vertical)

(ii) State two ways on how information & communication technology (ICT) can be used to reduce the spread of HIV/ AIDS ( 2 mks)

  • Through advertisements on the Internet
  • Through creation of posters
  • Through discussion groups on the internet

19. (a) Describe the following terms with reference to security of data:

(i) Log files

– A file that lists actions that have occurred. For example, web servers maintain log files listings every request made to the server. With log file analysis tools, its possible to get a good idea of where visitors are coming from, how often they return and how they navigate through a site.

ii) Firewalls. (1mark)

A firewall is an information technology (IT) security device which is configured to permit, deny or proxy data connections set and configured by the organization’s security policy. Firewalls can either be hardware and/or software based.

A firewall!\s basic task is to control traffic between compeer networks with different zones of trust. Typical examples are the Internet which is a zone with no trust and an internal network which is (and should be) a zone with high trust The ultimate goal is to provide controlled interfaces between zones of differing trust levels through the enforcement of a security policy and connectivity model based on the least privilege principle and separation of duties

b) A students’ database comprises of students1 details table and fees received table as shown below:

Students’ details table Fees Received table

Surname Date

Middle Name Amount

First Name Receipt Number

Admission Number

Course

(i) State the primary key field for each table.

Student table- Admission Number

Fees Received table Receipt Number

ii) State the field, which should serve as the linking field for the two tables.

Admission number

(Note: Make Admission Number a foreign key in the fees table)

c) Describe the following terms with respect to computer security:

i) Logic bombs (2 Marks)

A computer virus that is activated after a series of event/commands/date

ii) Physical security (2 Marks)

Threats that threaten the physical nature of computer equipment e.g. Fire, Lightening water, building access etc

iii) Tapping. (2 Marks)

Telephone tapping (or wire tapping/wiretapping) is the monitoring of telephone and Internet conversations by a third party, often by covert means. The telephone tap or wire tap received its name because historically, the monitoring connection was applied to the wires of the telephone line of the person who was being monitored and drew off or tapped a small amount of the electrical signal carrying the conversation

(d) List three functions of antivirus software.

Identify a virus/Warn

Heal/Clean a virus

Prevent/Protect infection

Quarantine infected files

20 (a) The diagram below shows four common network topologies A, B, C

Pg110 00_0and D.

i) Name the network topologies labeled A, B, C and (4 marks)

A Tree/Hierarchy

B Ring

C Bus/Multi drop

D Star

ii) Explain what happens if server X in topology A fails. (1 Mark)

The terminal connected to X will be affected/stop communicating with the ret of the network

iii) List two problems associated with network topology B. (2 Marks)

Difficult to trouble shoot “- Failure of one terminal results in network breakdown

– Extra cost of extra NIC card.

iv) List two disadvantages associated with network topology D. (2 Marks)

Failure of central device/server results I total collapse of network

Extra cost of cabling as each terminal must be cabled separately to the hub.

b) Differentiate between Internet and World Wide Web. (2 Marks)

The Internet is a massive network of networks, a networking infrastructure. It connects millions of computers together globally, forming a network in which any computer can communicate with any other computer as long as they are both connected to the Internet. Information that travels over the Internet does so via a variety of languages known as protocols.

The World Wide Web, or simply Web, is a way of accessing information over the medium of the Internet It is an information-sharing model that is built on top of the Internet The Web uses the HTTP protocol, only one of the languages spoken over the Internet, to transmit data. Web services, which use IfTTP to allow applications to communicate in order to exchange business logic, use the Web to share information. The Web also utilizes browsers, such as Internet Explorer or Netscape, to access Web documents called Web pages that are linked to each other via hyperlinks. Web documents also contain graphics, sounds, text and video.

c) Describe the following network services and identify their

applications. (2 Marks)

i) Voice mail (2 Marks)

Voicemail (or voice matt, voicemail or VMS, sometimes called message bank) is a centralized system of managing telephone messages for a large group of people. In its simplest form it mimics the functions of an answering machine, uses a standard telephone handset for the user interface, and uses a centralized, computerized system rather than equipment at the individual telephone.

Voicemail systems are much more sophisticated than answering machines in that they can:

Answer many phones at the same time

– Store incoming voice messages in personalized mailboxes associated with the user’s phone number

– Enable users to forward received messages to another voice mailbox

send messages to one or more other user voice mailboxes

Add a voice introduction to a forwarded message

-Store voice messages for future delivery

Make calls to a telephone or paging service to notify the user a message has arrived in his/her mailbox

– Transfer callers to another phone number for personal assistance

– Play different message greetings to different callers.

ii) Video conferencing. (2 Marks)

A videoconference (also known as a video teleconference) is a set of interactive telecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions simultaneously. It has also been called visual collaboration and is a type of groupware.