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)

•  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

a. Data Loss: Sudden power outages or voltage fluctuations can cause the computer to shut down abruptly, resulting in data loss if unsaved work is not properly stored. This can be particularly problematic when working on critical tasks or handling important files.

b. Hardware Damage: Power surges or inconsistent power supply can damage the computer's internal components, including the motherboard, CPU, memory, and storage devices. These damages can result in system instability, reduced performance, or even complete hardware failure.

c. Operating System Corruption: Abrupt power loss or inconsistent power supply can corrupt the operating system files, leading to system crashes, error messages, and instability. This may require system repairs or reinstallation of the operating system.

d. Component Lifespan: Inconsistent power supply can put unnecessary stress on computer components, shortening their lifespan. Frequent power fluctuations or surges can cause wear and tear on various parts, reducing their efficiency and overall longevity.

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