HTTPS/HTTP: this is a protocol that is used to send data to web pages across the Internet

Uniform Resource Locator (URL):   a text-based version of a web address

Internet Service provider /ISP  - his is the company that provides a user with a connection to the Internet

browser - Software/application that allows users to view web pages / render HTML -

cookie - a text file (stored by a web browser) that contains data about a user’s browsing habits/details/preferences

Number of cores
The number of cores a processor has directly affects the performance of the processor. Each core can perform its own fetch-execute cycle independently of others, so different applications can be allocated to different cores. Quad-core (four-core) and even octa-core (eight-core) processors are becoming common

Cache memory
A processor’s cache is a small portion of incredibly fast memory. It has read and write speeds far higher than hard disk drives and even SSDs. The cache is used to store frequently used information and reduces time wasted in fetching the same information from main memory time and time again

Clock speed
A processor’s clock speed relates to the frequency of the pulses generated by the system clock. The higher the frequency, the more cycles of the fetch-execute cycle can be completed in the same period of time.

Word length
A word is a group of bits that is treated as a single unit by a processor. Words can be used for representing both instructions and data. The length of a word is the number of bits that are assigned to it, with higher word lengths allowing for more bits to be transferred and manipulated as a single unit.

Address bus width
The width of a bus relates to the number wires that make up the bus. Increasing the width of the address bus increases the range of addresses that it can specify, hence increasing the computer’s amount of addressable memory. Adding a single wire doubles the number of addressable memory locations

Data bus width
Increasing the width of the data bus increases the volume of data that can be transferred over the bus at any one time. A wider data bus allows the processor to fetch more data from the main memory in one cycle of the fetch-execute cycle, reducing the number of cycles required to fetch large volumes of data.

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.

• Main document
• Data source
• merged document

1. Use a humidifier: Using a humidifier can help maintain a consistent level of humidity in the computer lab, which can prevent the negative effects of low humidity.

2. Avoid dry air: Avoid creating a dry environment in the computer lab by opening windows or using fans to increase air circulation.

3. Regular maintenance: Ensure that all computer components are properly maintained and cleaned to prevent damage due to static electricity.

4. Backup data: Regularly backup all important data to avoid data loss in case of hardware failure caused by low humidity.

5. Monitor humidity levels: Use a hygrometer to monitor the humidity levels in the computer lab and take corrective measures if the levels fall below a safe range.

6. Use anti-static materials: Use anti-static mats or wristbands when handling computer components to prevent static electricity buildup.

Solid state
 

• High-level languages have built-in functions;
• High-level languages have built-in libraries;
•  High-level languages have more support/help;
• High-level languages have structures (such as selection and iteration);
• High-level languages can be less machine-dependent/more portable;
• It (usually) requires fewer lines of code to be written;
• It is (usually) quicker to develop code in high-level languages;
• It is easier to find mistakes in code;
• The code is easier to maintain//understand;
• • It is easier to structure code in high-level languages;

• Serial is the transmission of data one bit at a time/through one wire
• Parallel is the transmission of data more than one bit at a time/many wires
• Simplex is the transmission of data in one direction only
• Duplex is the transmission of data in both directions simultaneously

SECTION A (40 MARKS)

ANSWER ALL THE QUESTIONS IN THIS SECTION

1.Compare the two types of diskettes used in microcomputers in terms of physical size and densities.    (2mks)

2.Why is it necessary to have a UPS in a computer laboratory?  (2mks)

3 a) Explain what is meant by batch processing   (1mk)

   b) Give one advantage and one disadvantage of batch processing ( 2mks)

4. List any four high level programming languages  (2mks)

5.A 3 by 4 matrix M is to be added to another 3 by 4 matrix array N so as to give a third 3 by 4 matrix array P.  Using a high level programming language, write a program segment that assigns the sum of M and N to P.(4mks)

6. The first column in the table below contains the formulae as stored into the cell F10 of a spreadsheet.  Enter the formulae, as they would appear when copied to the cell M20 of the same spreadsheet.  (3mks)

7.  Give three advantages of separating data from the applications that use the data in database design. (3mks)

8.  Explain the impact of information on organizations in each of the following areas:  (2mks)

   a) Competition

   b) Pace of growth

9. a) List any four tasks that an electronic spreadsheet should be able to perform other than calculations  (2mks)

    b) Explain what is meant by automatic recalculation as used in a spreadsheet.(1 mk)

10. Describe the functions of the following computer hardware components:

   a)Mouse                     (2 ½  mks)

   b)Scanner.                   (1 ½ mks)

11. a)State two differences between Disk Operating System (DOS) and WINDOWS operating system.

 b. i) Define the term application software  (1mk)

     ii) Give one example of application software (1mk)

12. a)  Give one difference between internal and external commands in Disk Operating System.   (2mks)

      b)  Name two DOS commands that may be used for checking disk errors.  (2mks)

13. Explain how a paragraph can be moved from one place to another in word-processing. 2mks)

14.  Define the term structured programming. (2mks)

SECTION B (60MKS)

Answer question 15 and any other three questions from this section.

15.a)  What is meant by each of the following terms:

 i)   pseudocode        (1 ½ mks)

  ii)  Flowchart           (1 ½ mks)

b) a program is required to list the first 1000 numbers in the series:  2, 4, 6, 8,

10. Draw a flowchart and write a program that can be carried out this task.   (12 mks)

16. The following car details are to be entered in a database; make, date-of-manufacture, colour and cost.

 a) Prepare a suitable database structure showing field names and their field types   (5mks)

 b) Explain how you index the data such that cars of the same make and colours are together   (2mks)

 c)  Write a statement that can be used to select cars of the colour green        (2 mks)

 d) Give an instruction that would;

  i)select cars whose cost lie between 500,000/= and 1,000,000/=  (3 mks)

 ii)Determine the average cost of all cars         (3mks)

17.  a)The diagram below represents the essential features o a computer system. Study the diagram and answer the questions that follow:

i)Name the components (4mks)

            A

            B

            C

            D

ii) On the diagram above, indicate the direction of data flow using arrows.  (3mks)

b) Name the three types of buses in a computer system (3mks)

c) Explain how CPU registers may be used to carry out a basic calculation such as:2 + 7 = 9

d) Name two computers output devices. (1 Mark)

18. a)State three ways in which computer technology may affect employment patterns in organizations   (3mks)

b) State three ways in which computer technology may affect employment patterns in organizations (3mks)

c)Suggest three strategies that can be employed to manage resistance to change  (3mks)

d) Give three advantages of computerization in an organization.  (3mks)

19. a)In a computer based information system, state the purpose of the following files and give one example where such a file may be required in a school.                (8mks)

i) report file

ii)Back-up file

iii)Reference file

iv) Sort file

b) State three precautions that should be taken to ensure that diskettes are well stored.  (3 mks)

c)  Distinguish between “serial” and Indexed sequential” file organization methods.  (2mks)

d)  Distinguish between binary and octal number systems and give an example of each  (2mks)

Direct Change-Over

• A date is chosen for the shutdown of the old system, then at that time, the old system
  is turned off and the new system is implemented

Phased

• Parts of the new system are implemented in stages or for a period of time, both the old and the new system are running together until all parts of the system are implemented.

• 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

Advantages

•  A touch screen is very intuitive
• Easy to use as the user simply touches what they see on the display
• Save space as no keyboard or mouse is required.
• Touch monitors can even be mounted on the wall.
• Touching a visual display of choices requires little thinking and is a form of direct manipulation that is easy to learn.
• Touch screens are the fastest pointing devices.
• Touch screens have easier hand-eye coordination than mice or keyboards.
• No extra workspace is required as with other pointing devices.
• Touch screens are durable in public access and in high volume usage

Disadvantages

• Difficult for people with accessibility issues, e.g no feedback, disability
• Can be easily damaged/scratched
• Damaged/scratched screen prevent the interface from functioning as it should
• Dirty screens difficult to read
• Users must be within arm’s reach of the display
• It is difficult to select small items
• User's hand may obscure the screen
• Screens need to be installed at a lower position and tilted to reduce arm fatigue
• Some reduction in image brightness may occur
• They cost more than alternative devices

17. a) i) Explain the term search as used in the Internet.                                            [2]

A web based application that locates items or information from the World Wide Web

ii) Peter intends to download a movie from the Internet. State the three factors that may determine the total time taken to complete the download.                                           [3]

• Size of the video/format
• The bandwidth of the media/speed of network/network traffic
• Type of browser software
• Background activities running in the computer
• Restrictions enforced in the computer/firewall/antivirus
• Speed of the computer/CPU speed
• Size of RAM

b) Wakulima online is an organization that runs a web based system for assisting farmers to obtain market for their produce. State four technological reasons that may cause a farmer not to access the organization’s system.                                                                                  [4]

• Poor network/lack of connection
• Software failure in the system

• Hardware failure
• Lack of access rights
• System overload/hanging
• Lack of skills/disability/illiteracy
• Lack of power supply

c) Explain a situation when each of the following Desktop Publishing program features may be used when creating a publication:

i. Cropping                                                                                                               [2]

Applies to graphics – used to trim/remove/hide some portions in the graphics

ii. Transparency                                                                                                         [2]

Used to make background of a graphic to be clear/visible

d. List two areas where infrared waves are used in data communication.                             [2]

18. a) List four activities of the planning stage of systems development.                             Ignore this question, marks redistributed elsewhere

b) Explain a circumstance when each of the following feasibility studies are carried out during systems development.

i. Technical                                                                                                               [3]

Done to determine whether technology exists to support the proposed solution

ii. Economic                                                                                                              [3]

Done to determine whether the proposed solution is economically viable

iii. Schedule                                                                                                               [3]

Done to determine whether the proposed system can be done within an acceptable time.

c) Table 1 and Table 2 are related tables in a database. Use them to answer the questions that follow.

Table 1

Table 2

i. Identify the appropriate primary key for each table.                    [2]

Table 1 – Dept code, Student Registration No

ii. Explain two benefits of enforcing referential integrity in the database. [4]

• No record can be added in Table 2 if its corresponding record in Table 1 does not exist
• No record in Table 1 can be deleted without first deleting the corresponding record in Table 2
• Reduces data redundancies/ensures integrity
• Prevents deletion of related table

19. a) Describe each of the following validation checks as used in data processing.

i. Preserve check                                                                                                      [2]

Ignore this question, marks redistributed elsewhere

ii. Data type check                                                                                                    [2]

Ensure correct type of data is entered for the field

iii. Check digit                                                                                                           [2]

This is a number added/calculated by the computer to a binary number. The check digit ensures correct transmission of the binary number.

b. Write each of the following abbreviations in full:

i) BCD                                                                                                                                    [1½]

Binary Coded Decimal

ii) EBCD                                                                                                                                 [

This question was thrown out and marks redistributed elsewhere

iii) ASCII                                                                                                                    [1½]

American Standard Code for Information Interchange

c) Using 10-bits binary number system, perform the following decimal operation using two’s complement.                                                                                                                                   [6]

12910 - 12810

+129 = 00 1000 0001

128 = 00 1000 0000

-128 = 11 0111 1111 (ones complement)

                            +1

          11 1000 0000 (Twos complement)

129- 128

     00 1000 0001

+ 11 1000 0000

 100 0000 0001

Hence = 00 0000 00012 or 12 (the overflow bit is ignored)

• No licence agreement as a certificate of authenticity
• Prices that are extremely cheap
• No documentation manual
• when one connects to the internet for authentication, the report from the manufacturer indicates that the user may be a victim of software counterfeiting
• frequent runtime or occurrence of fatal errors when using the machine

a) What is an operating system? (1 mark)

• It is a system software that manages the computer hardware. It provides a platform for installation & execution of application software.

b) Briefly explain any four functions of an operating system. (8 marks)
Interrupt handling - When an interrupt occurs, the current state of the CPU is saved & the OS handles the request, after which the OS restores the previous state of the CPU & resumes the interrupted process.
Process scheduling - OS decides which process runs next & for how long.
Memory management - Ensures that each process has enough memory allocated to execute without interfering with other processes.
Error handling - OS provides a mechanism to detect & respond to errors such as segmentation faults, hardware failures, or invalid instructions.

(i) Crop - 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 background of a graphic visible

(a)

– webcam
– speakers
– microphone
– broadband modem

(b)

– use of CODEC (converts/compresses analogue data into digital data)
– echo cancellation s/ware (allows talking in real time/keeps everything in sync)
– compression s/ware for video/audio
– s/ware to access broadband/networking

• The process of rewriting parts of a file to contiguous sectors on a disk

Legend

• Legends are a small visual representation of the chart's data series to understand each without confusion.

A data series

• is a row or column of numbers that are entered in a worksheet and plotted in your chart, such as a list of quarterly business profits
• A group of related data points or markers that are plotted in charts and graphs

Data Marker

• A symbol on the chart that represents a single value in the worksheet.
• A column, dot, pie slice, or another symbol in the chart that represents a data value

• Overtype mode: deletes the current text at the cursor position and replaces the existing characters with new text
• Insert Mode: pushes the existing text away as new text is inserted between the existing text