admin@kcseforecast.com

Q&A-KCSE Computer Studies Paper 1

State three ways of transforming a picture embedded in a DTP program in order to fit on a designated space on a document (kcse 2019 paper 1)

  • Resizing using resize handles
  • Rotating
  • Cropping
  • Flipping
  • Moving
Question Image

Convert the following:

(a) the binary number \(1111 1100_2\) to hexadecimal.

(b) the denary number \(138_{10}\) to hexadecimal.

(c) the hexadecimal number \(5D_{16}\) to denary.


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

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

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

Question Image

When data is transmitted it is subject to corruption. Explain how a parity check could be used to determine whether corruption has taken place.

  • Extra bit on each data-byte that
  •  Does not transmit data
  • Makes the number of ones in a byte always even or always odd
  • Error in the transmission of a bit will make the even/odd wrong
  • The problem of two errors in one byte not being found
  • Parity block
Question Image

A computer is upgraded to a dual-core CPU.
Explain how the upgrade can affect the performance of the computer.

  • It can now process two instructions simultaneously (where suitable) increasing the performance.

 

Question Image

(a)Explain why programmers prefer to represent instruction in hexadecimal rather than in binary

  • A larger number of values can be represented using fewer characters.
  • the shorter length and more characters make the pattern easier to read and understand
  • recognisable character codes can be used for debugging

(b) Give two other uses of hexadecimal

  • HMTL color codes representing RGB spectrum in the web development
  • representation of MAC and IP addresses allowing a larger combination of unique addresses

(a)Explain why programmers prefer to represent instruction in hexadecimal rather than in binary

  • A larger number of values can be represented using fewer characters.
  • the shorter length and more characters make the pattern easier to read and understand
  • recognisable character codes can be used for debugging

(b) Give two other uses of hexadecimal

  • HMTL color codes representing RGB spectrum in the web development
  • representation of MAC and IP addresses allowing a larger combination of unique addresses
Question Image

Why must operating system be installed in a computer before any other program

  1. Operating system manages the computer hardware thus without it the programs cannot communicate directly to the hardware
  2. Provide a user interface through which a user can give instructions to the computer. Without a user interface, it would be difficult to load or run programs
  3. other programs depend on the operating system to load them into the memory , allocate resources and schedule processor time, Without operating , there would be nothing to co-ordinate the execution of multiples programs
  4. The OS organizes data in files and directories, making it possible for programs to save, retrieve, and modify data.
  5. Without it, programs wouldn’t know where or how to store data.
  6. The OS controls access to files, memory, and devices, ensuring that one program doesn’t interfere with another.


Question Image

Maranda 2024 Mock CRE Paper 2

1. a) Based on Deutro-Isaiah, describe the Messiah. (7mks)

The Messiah would be despised/ rejected

The Messiah would be treated harshly/ arrested/sentenced to death

The Messiah would be reconciling people through His suffering

The death of the Messiah would bring forgiveness of sins of humankind

The Messiah would endure suffering/humiliation without complaining/ would suffer innocently

The Messiah would have nothing attractive

The Messiah would be humble/simple

The Messiah would be highly honored

The Messiah would succeed in His work

He would be despised, rejected, wounded oppressed and afflicted 

He endured pain and suffering which would have been ours. 

Because of our sins he was wounded 

We are healed by the punishment he suffered He was treated harshly but he never said a word 

He was put in the grave with the wicked 

He was buried with the rich even though he did not commit a crime 

He took the place of many sinners and prayed that they might be forgiven.

 

Question Image

State three different methods that allow people to communicate using the Internet. In each case, give a different benefit for the stated method.

emails: – fast delivery of messages (to recipient’s mail box)
– able to send attachments
– can store messages for later use
– auto-translation no language problems
– can open email at a convenient time
video conferencing/calling/chat:
– removes need to travel (saves time and money)
– allows face to face discussions
– works in real time (only allow once)
VoIP: – much cheaper than normal international calls
– direct communication between people
– works in real time (only allow once)
chat rooms/instant messaging:
– instantaneous reply
– anyone can join in
social networking:
– can ensure only your “friends” are in communication
– usually free to join and use
– talk to (multiple) friends at the same time

Question Image

Ahmed uses the Internet for some time and is puzzled by the terminology.
(a) Draw a line to match each description to the appropriate technical term.

  • a computer that responds to requests to provide information and services over the Internet - an Internet server
  • defines how messages are transmitted and formatted over the Internet-HTTP
  • software that enables users to access/view documents and other resources on the Internet - Browser     
  • numerical ID for each device on the Internet-IP address
  • unique ID for a network interface card  -MAC address
Question Image

State the advantages and disadvantages of the command-line interface

Advantages

  • It is quicker to type commands
  • Little memory needed
  • Little processing power needed

Disadvantages

  • Commands have to be typed precisely
  • There is a large number of commands to be learnt
  • It is not user friendly
  • The user has to remember commands
  • Users cannot transfer data between applications
Question Image

Identify one component common to all computers.

  • Processor
Question Image

Define the term variable as used in programming

A variable is a memory location used to store a value

Question Image

A web server has an internet protocol (IP) address. Give three characteristics of an IP address.

  • 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.
Question Image

State the functions of the following features in word processors

  • Thesaurus - Is a feature in a word processor that suggest words with the similar or opposite meaning to the one selected
  • Comments: a feature in a word processor that allows a user to attach a remark about the selection
Question Image

Briefly describe the information Security principles or CIA triads

  • confidentiality - The principle of protection from unauthorized access or disclosure
  • Integrity - the principle of ensuring that unauthorized or undetected changes to data or system configurations do not occur.
  • Availability - the principle of ensuring that data and services remain accessible to authorized users at all times

 

Question Image

Describe two benefits of using USB connections between a computer and a device.

  • devices are automatically detected and configured when initially attached
  • Impossible to connect device incorrectly/connector only fits one way
  • has become the industry standard
  • supports multiple data transmission speeds
  • lots of support base for USB software developers
  • supported by many operating systems
  • backward compatible
  • faster transmission compared to wireless
Question Image

List four input devices used to capture data by way of scanning                 

Optical Mark Recognition; Optical Character Recognition; Magnetic Ink Character Recognition ; Optical Bar Recognition

Giving answers as readers is also acceptable, that is, Optical Character Readers, Magnetic Ink Character Readers; Optical Mark Readers

 

Give three examples of how data can be damaged accidentally

  • Power surge/loss (damages hardware)
  •  Use a UPS
  • Water can be spilt on the device
  • Don’t have water near the device
  • Keep the device in a waterproof box when not is use
  • Fire can destroy the device
  • Use electrics safety
  • Keep the device in a fireproof box when not in use
  • Data is accidentally deleted
  •  Add verification method for data deletion
  •  Set access levels for data to limit who can delete the data
  • Incorrect use of storage device
  • Making sure the device is ejected before removing
  •  Physical damage to hardware // hardware failure
  •  Correct care and maintenance of hardware
  •  Software failure 
  • Making sure it is always up to date // enable automatic updates

 

Question Image

Describe three possible threats to the computers connected to the network and give one way each threat can be reduced or prevented

Virus / trojan / worm / malware

  • Piece of software/code/a program that replicates itself  or causes damage e.g. editing/deleting files

Prevention

  • Running anti-virus/anti-malware software 
  • don’t download from unknown sources
  • don’t click on unknown links

Spyware / malware / keylogger

  • Piece of software/code/a program that records actions/key presses and sends this data to a third party analysis

Prevention

  •  Running anti-spyware/anti-malware software/firewall

Data interception / passive

  • Data is sent to another device and is intercepted by a third party

Prevention

  • Encryption

Phishing

  • An e-mail has a link that when clicked directs the user to a fake website that collects personal data

Prevention

  • Network policy // firewall

Pharming

  • A piece of code installed that redirects user to fake website that collects personal data

Prevention

  • Anti-malware or firewall

Hacker

  • Person attempting to gain unauthorised access to the network/computers/ data/files 
  • unauthorised access and then deleting/editing data/files

Prevention

  • Firewall
  • strong password 
  • biometrics
  • penetration testing
Question Image

Define the following modes of electronic data processing:

  1. Multitasking
  2. Real time processing
  3. Timesharing
  4. Online Processing

Multi-tasking - It is a data processing modes where a single CPU processing more than one task or program apparently at the same time

Time-sharing - a processing mode where a single CPU processes tasks from more than one user apparently at the same time

Time-sharing - this is a processing mode in which the CPU serves two or more users with different processing requirements ( tasks)

On-line processing - is a mode of processing where the result of data processing transaction is available immediately

Real-time processing - is a mode of data processing in which the time interval required to process and respond to inputs is so small that the response itself is useful for controlling the physical activity of a process

Question Image