(a) \(F C_{16}\)

(b) \(8 A_{16}\)

(c) \(93_{10}\)

• Detecting congestion.
• Synchronizing activity between traffic lights.
• Updating traffic light timing in real time.
• Updating and informing drivers of ideal speeds.
•  Prioritizing transportation flow.
•  Reduce congestion and time spent on the road
• By reducing congestion it will decrease pollution
• Prioritize traffic based on changes in traffic conditions in real time.
• This system is also helpful to reduce infrastructure damage. It is possible to identify overloaded vehicles and provide them with appropriate ways or roads, which will reduce road damage.

• Making prosthetic limbs for patients
• Making items which allow precise reconstructive surgery
• Making light-weight plane wings
• Making sculptures

Is an arrangement of people, data, processes, communication and IT that interact to support problem solving

Components of an information system

• Hardware
• Software
• Data - information manipulated by software
• people- all people involved
• Processes - steps to accomplish a goal

• Easy to add nodes
• Managed centrally
• Fewer data collisions
• A single node failure does not affect the rest of the network

State the function of each of the following keys on the computer keyboard :  (2mks)

Backspace;

• Deletes characters to the left of the cursor

Insert

• Add characters at the cursor position
• Toggles between overtype and insert modes

An organization intends to replace an existing system by carrying out the process in stages .

Name the implementation strategy ;  (1mk)

• Phased change-over

Give two reasons why the  organization is opting to use the implementation strategy  in (a) above (2mks)

• Gives employees time to learn
• Organizations can revert to the old system in case of failure
• Reduces resistance by the employee
• It is easier to find system errors as you are dealing with only one part at a time
• Accessing parts of the old system is still is possible in case of failure of the new system

Advantages

• no wires
• fast/high-speed wireless Internet access
• WLAN is faster than a modem or mobile
• WLAN for working at home one day a week/teleworkers
• see internet content away on the move
• create and send multimedia messages to mobiles or e-mail
• picture messaging - send photos/pictures text/sound/recorded
• greetings from mobiles to mobiles/PCs
• instant transmission - no busy signals/no searching for phone jacks
• download e-mail and file attachments on mobile
• watch live webcast on mobile/hotspot
• listen to streaming video on mobile/hotspot
• news/weather/sport/games while on the move
• access information from mobile anytime
• send/receive/delete e-mail while on the move
• wireless Inbox on mobile - to contacts and calendar
• view business appointments while out of the office on mobile
• send corporate e-mail while out of the office - even behind a firewall on mobile
• wireless internet connection from chat rooms for discussions with colleagues while on the move
• give visual demonstrations from mobile and colleagues watch back at the office

 disadvantages e.g.

• WLAN speeds are slower than Net access at work/narrow band width
• any one within the WLAN nodes range with an appropriate device can use your WLAN and broad band link
• any one who walks past your house or WLAN linked into a corporate system can access sensitive information or credit card details
• 3G phones not compatible with 2G phones
• Blue tooth - has limited range
• blocked signal/distorted signal/weak signal/lag
• health problems from microwaves

• Guided media uses cables to connect to computers whereas unguided media uses waves.

1.State two reasons for the increased use of laptop computers in government offices. [2]

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 integrated together

Easy to share

Have rechargeable battery

Have low power consumption

2.Computer network technicians prefer to use command-line based operating systems when configuring networks. State three reasons for the preference. [3]

Do not take up a lot of memory

Have direct access to most hardware devices/provide complete control during configuration

Cheaper to acquire as some are freeware/shareware

Faster to execute commands

Difficult to hack/more secure

More stable

3.State three measures that should be put in place in a computer laboratory to safeguard users’ health. [3]

• All power cables must be insulated and hidden from users
• Furniture used must be of standard
• Room should have adequate lighting
• No overcrowding
• Monitor should be fitted with anti glare
• Avoid dust
• Avoid slippery floor
• Avoid bright coloured walls
• Promote use of ergonomic devices

4.State three ways in which barcode readers may be used in schools. [3]

Take inventory of items

Transactions in the school library

Keep track of movement of goods

Track students in and out of school

Used to register roll call

5.State three advantages of flat panel monitors over cathode ray tube monitors as used in computers.                                                                                                                     [3]

• Compact and light/portable/less bulky/occupy less space
• Consume less power
• Low angle distortion
• Improved color depth
• Higher resolution
• Have less radiation
• Produce less heat

6.State three possible reasons for the extinction of daisy wheel printers in the market. [3]

• Slow
• Noisy
• Lack of graphic support
• Monochrome printer
• Supported on font type and size

7.State three ways in which an operating system secures a computer system.             [3]

• User authentication
• Secure user accounts with privileges
• Encryption of data
• Keeping log files
• Auto backup and auto recovery features
• Inbuilt antivirus

8.A law firm prefers to use hard copy output when handling documents for legal matters. State two reasons for this preference.                                                            [2]

• Can be used without electricity
• Can serve as physical evidence/exhibit
• Not easy to change content without leaving evidence
• No need of computer knowledge

9.State the function of each of the following feature in a word processor

a. Thesaurus                                                                                                                    [1]

Feature that suggests words with similar or opposite meanings to the selected word

b. Comments                                                                                                                   [1]

Feature that allows a user to attach remarks

10. With the aid of an example, explain the term multi-level list as used in word processing.                                                                                                                [3]

1. Chapter 10
   1. Summary
      1. xxxxxxxx

Formatting style that shows listed items at different level instead of using one line

11. Distinguish between real-time operating system and distributed operating system. [3]

Accept answers based on data processing concept

12. Explain the function of protect sheet feature in a spreadsheet program.                   [2]

A tool/feature that prevents unwanted changes to the spreadsheet. Requires a user to key in a password inorder to make changes

13. State four computer based careers introduced as a result of computerized data processing method at the airport.                                                                                     [2]

• System analysts
• Web designers
• Network administrators
• Network technicians
• Programmers
• Database Administrators

NB/ Accept any computer based career

14. In a spreadsheet, the formula = If(A1>10,A1*77,A1*50) is entered in a cell. Interpret the results.                                                                                                                        [3]

Checks the value in cell A1if it is more than 10, if the comparison is true then the outcome of the value in cell multiplied by 77 is displayed, else if it is false the results of the value in cell A1 multiplied by 50 are displayed.

15. State a stage in systems development cycle where each of the following activities are carried out:

a. Identifying the technologies that may be used in a proposed system.                       [1]

Accept any sub stage within system analysis e.g. requirement specification, problem definition, information gathering, etc

b. Identifying shortcomings of a system.                                                                       [1]

All stages of system development

c. Preparing the system migration plan.                                                                          [1]

Implementation stage

• RSI in wrists or fingers from prolonged typing or repeated clicking of mouse button
• headaches/eyestrain/dry eye from staring at a monitor for long periods of time/glare from monitor
• back ache/strain from sitting in the  same position for a long time/using chair with no adjustment

• System software manages the computer hardware/application software
• application software is for end-user tasks

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)

• Used to resize the image
• Used to rotate the image
• Used to move the image

• Continually monitoring, evaluating and updating the system once it is operational. Activities include rectifying bugs, requesting changes, updating aspects, finding errors, maintaining code etc.

• Distributed data processing is where computers located in physically separate location transmit data after processing to a server computer that updates the master file. Time-sharing on the other hand is where various terminals transmit data to be processed by a central computer's CPU. Each terminal's tasks are allocated a time slice of the CPU

• Repeaters : amplify data signal thereby extending the physical coverage of a network. It can connect two LANs locally.
• Bridges: connect similar types of networks e.g a token ring to another token ring
• Routers: link networks of different types
• Gateway: allows computers in a network to connect regardless of their topology

A backup is a copy of data that can be used if the original data is lost.

• 4 (four)

The user is not allowed to access the source code so, they cannot tailor the software to their needs and  they cannot fix any bugs in it

The software is still covered by copyright

The user must get the owner’s permission to do anything beyond using it