• to enable logon information to be kept on his computer
• to provide pages customised for Ahmed the next time he logs on
• to implement shopping carts and one-click purchasing
• to be able to distinguish between new and repeat visitors to the website

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 employees
• 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

A manager wishes to replace the current manual system with a computerized one. Describe three areas that must be evaluated to justify the replacement  (6 marks)

• Technical feasibility

• Does the current technology suffice

• Economic feasibility

• Benefits outweigh costs/ whether the project is cost effective

• Schedule feasibility

• Can it be done within the schedule

Headache, back and neck pain may result from the use of computers. State how each of them can be minimized                               (2mks)

• Proper lighting
• Regular breaks
• Use of antiglare
• Correct position of the screen
• Ergonomic furniture

Students of a school intended to elect their school Captain by secret ballot.  State three ways in which computers can be used to improve the election process                          (3mks)

• Registrations of voters
• Voter identification
• Actual voting
• Tallying

Explain why intranet is a more secure way to share files within an organization compared to internet (2mks)

• Intranet involves the interconnection of computers  within  the organization hence it is easier to monitor the access and sharing of files since the users in an organization can be assigned accounts and passwords which will enable to access files they are authorized to access unlike the internet where many can access what is stored in the organization’s website

List two career opportunities directly associated with computer networking               (2mks)

• Network administrators
• Network engineers
• Network technicians

Distinguish between a formula and a function as used in spreadsheets

• A formula is a mathematical expression that returns a value
• A function is an excel inbuilt formula that returns a value given a range of values or arguments

 The C directory of a computer has folders named Form 1, Form 2, Form 3 and Form 4. Each class has students’ folder named according to their admission number.  The student created their own folder for subjects they are studying based on the table below:

• camera film speed, position (end of film), distance, light
• washing machine amount of water, speed of wash/temperature/time
• fridge temperature, display panel
• air conditioning temperature, timing, display pane

Both translate source code written in high level programming languages into machine code.
Compiler: Produces a single executable file that is portable between machines
Interpreter: Source code needs a special environment to run
Compiler: Needs to be compiled for a particular architecture
Interpreter: Can run on any architecture that has the translator/interpreter
Complier: Entire source code file is translated at once
Interpreter: Code is translated line by line
Compiler: Provides error report at the end of the compilation
Interpreter: Errors more obvious in the sequence
Compiler: The program source code is not available (so helps protect IP)
Interpreter: Source code is available
Compiler: Only has to be translated once (affecting the speed of execution)
Interpreter: Has to be translated each time, therefore (affecting the speed of execution)
Compiler: Requires two files to be maintained (one for execution and for editing purposes)
Interpreter: Requires only one file to be maintained
 

Input : An algorithm can take 0 or more inputs well defined outputs

Finiteness: an algorithm must terminate in finite time and after finite number of steps. 

Definiteness : an algorithm must be clear and unambiguous. Each and every step of an algorithm must be clear and precise and it must have only one meaning

Feasibility: should be feasible with the available resources

Output : must produce at least one well defined output

Independent : should have a step-by-step directions which is independent of any programming language

Correctness: should solve the problem it is designed to solve

Efficiency: must take the shortest time possible to run and should require the least memory space. It should use a minimum number of computation steps and memory to produce the desired  output. takes little time and memory to run

Generality: should not be limited to a specific case. It should work for all the valid inputs. works for many possible inputs

Effectiveness : should statements that are relevant to the problem. Every step must be basic and essential. 

• consists of values between 0–255 / 0–FFF
• values are separated by full stops/colons
• it is a unique address
• can be static or dynamic
• can be public or private
• can be IPv4 / have four groups of digits
• can be IPv6 / have eight groups of digits
• in IPv6: can replace groups of zeros.

The data before encryption is known as .......plain.................. text.
To scramble the data, an encryption ......................key.........................., which is a type
of ...................key............................, is used.
The data after encryption is known as ....................cipher............................. text.
Encryption prevents the data from being ......................understood...................... by a hacker

• System software that analyses, configures, optimises and maintains a computer system

highest = -1
for student = 1 to 3000
total = 0
for exam = 1 to 8
input mark
total = total + mark
if mark > highest then highest = mark
next
average = total/8
output average
next
output highest

Python code:

highest = -1
for student in range(1, 3001):
    total = 0
    for exam in range(1, 9):
        mark = int(input("Enter mark: "))
        total += mark
        if mark > highest:
            highest = mark
    average = total / 8
    print("Average:", average)
print("Highest mark:", highest)

VBA Code

Option Explicit

Sub CalculateAverageAndHighest()
    Dim highest As Integer
    Dim total As Integer
    Dim mark As Integer
    Dim average As Double
    
    highest = -1
    
    For student = 1 To 3000
        total = 0
        For exam = 1 To 8
            mark = InputBox("Enter mark:")
            total = total + mark
            If mark > highest Then
                highest = mark
            End If
        Next exam
        average = total / 8
        MsgBox "Average: " & average
    Next student
    
    MsgBox "Highest mark: " & highest
End Sub

• College authorities are the experts in the problem
• A system Analyst is an expert with computers
• The two need to pool resources to come up with a clear definition
• Agree on the outcomes so that when the system is , there are a set of criteria to judge it by

• An instruction is retrieved from the memory
• The instruction is decoded
• The instruction is executed
• the program counter is incremented

State four threats that compromise data integrity

• Human error
• natural disaster
• data transmission errors
• software bugs

How threats to data integrity can be minimised:

• Backup data preferably on an external storage media
• control access to data by enforcing security measures
• design user interfaces that minimise chances of invalid data entry
• using error detection and correction software when transmitting data over the network
• using devices that directly capture data from the source such as bar code readers, digtal cameras, and optical character readers

• Labels
• Values
• Formula
• Functions

1. Primary Storage (Memory):

   • Random Access Memory (RAM): This is a volatile memory used to store data and instructions that the CPU (Central Processing Unit) can access quickly. RAM is essential for running applications and the operating system. However, its contents are lost when the computer is powered off.
   • Read-Only Memory (ROM): ROM is a non-volatile memory that stores essential firmware and instructions necessary for the computer's boot-up process. It retains its contents even when the power is turned off.
   • Cache Memory: Cache is a small and fast memory located closer to the CPU. It stores frequently accessed data to speed up the processing.

2. Secondary Storage (Mass Storage):

   • Hard Disk Drive (HDD): HDDs use magnetic storage to store data on rotating platters. They provide relatively large storage capacities and are commonly used in computers and laptops for long-term data storage.
   • Solid-State Drive (SSD): SSDs use NAND flash memory to store data, offering faster read and write speeds than HDDs. They are more durable and consume less power, making them increasingly popular in modern computers.
   • Optical Discs: CDs, DVDs, and Blu-ray discs are examples of optical storage media. They are mainly used for distribution of software, music, movies, and archival purposes.
   • USB Flash Drives: Also known as thumb drives or pen drives, these portable storage devices use flash memory to store data and can be easily connected to a computer's USB port.
   • Memory Cards: Memory cards, such as SD cards and microSD cards, are used in various devices like cameras, smartphones, and tablets to store data, photos, videos, etc.
   • External Hard Drives: These are HDDs or SSDs contained within an external enclosure, allowing users to expand their computer's storage capacity or create backups.

Manages memory (RAM)

•  Allocates memory to programs currently executing 

Ensures programs/data do not corrupt each other

• Ensures all programs and data including itself is stored in correct memory locations

Manages processes

• Ensures different processes can utilise the CPU and do not interfere with each other or crash  

Allows the user to run programs 

• On a multitasking operating system, it ensures that all tasks appear to run simultaneously 

Other roles

• Allocates time slices
• Scheduling of programs
• Handles interrupts
• Allows the user to configure hardware

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

• 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

• To provide legal backing so that it is possible to seek redress if the rights are violated
• To observe copyright for those who create original works
• To protect the confidentiality of information kept  about an individual

(a) Describe three effects this would have on the work force

• loss of jobs/unemployment
• deskilling
• need to re-train
• different jobs available/re-skilling
• no longer need to do hazardous/tedious jobs

(b) Give two advantages to the company of introducing robots

lower work force costs (no salaries to pay)

• lower environmental costs (less electricity for heating/lighting)
• higher throughput
• more consistent product
• robots don’t need breaks, holidays/work 24/7 etc.
• robots don’t take industrial action

(c) How could the robots be trained to assemble the televisions?

• tasks repeated by skilled worker and how each task is done is memorised
• tasks programmed directly into the computer/robot memor

(d) A whole batch of televisions was produced with some of the parts missing. How could this error have been avoided?

• if parts missing for a sequence, then a warning should be given and the assembly stopped
• several quality control stages to spot an error early on
• program in checks at each stage of assembly so robots can detect a fault immediately