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Q&A-KCSE Computer Studies Paper 1

Explain two computer hardware features that may be considered when selecting a laptop computer to be used in developing a KCSE computer studies project (4mks)

Multimedia Capability - A laptop with strong multimedia capabilities is essential for a computer studies project submitted on CD-RW. This ensures that the laptop can efficiently handle multimedia content, providing a seamless experience in creating and presenting project materials.

Processor Speed - Opting for a laptop with a high processor speed is crucial. This feature enables the smooth execution of multiple applications simultaneously, enhancing overall project efficiency and reducing processing delays.

Hard Disk Capacity - Consider a laptop with ample hard disk capacity, as the Microsoft Office suite used in computer projects requires significant space for the installation and storage of project files. A spacious hard drive ensures that there is sufficient room for data and applications.

Main Memory Capacity - Given that students often work with multiple programs concurrently during a project, it's important to choose a laptop with an adequate main memory size. A smaller main memory may result in performance issues, hindering the seamless operation of various software applications during project development.

 

Distinguish between transcription and transposition types of errors and give an example of each  (4mks)

Transcription Errors: Transcription errors involve the incorrect entry of data due to mistakes made during the copying or typing process. These errors can occur when transferring information from one source to another.

Transposition Errors: Transposition errors specifically refer to errors where the order of characters or digits is accidentally reversed or swapped. This can happen during manual data entry or when processing information.

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List three characteristics of Internet Protocol version 6 (IP6).

  • has a significantly larger address pool than previous version
  • features a client-side address assignment
  • has built-in encryption
  • enables one device to have many network addresses
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State two effects of a computer virus

  • memory used up/slows down computer/alters setting/systems failure
  • erases files/erases data/corrupts data/data needs restoring
  • infects other computers on the network
  • production loss/financial loss
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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

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List two types of network software

  • Network operating systems
  • Protocols
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What precautions would you take in a computer room in case a user complains of backache after long periods of using the computer?

  1. Ergonomic Chair: Ensure that each user has an ergonomic chair that provides proper lumbar support. The chair should be adjustable in terms of height and backrest angle.

  2. Adjustable Desk: Provide adjustable desks or workstations that can accommodate different user heights and allow for proper positioning of the keyboard, mouse, and monitor.

  3. Monitor Placement: Ensure that the computer monitors are positioned at eye level or slightly below to prevent users from straining their necks and shoulders. Consider using monitor stands or adjustable monitor arms for better positioning.

  4. Keyboard and Mouse: Encourage the use of ergonomic keyboards and mice that are designed to minimize strain on the wrists and hands. Provide wrist rests if needed.

  5. Proper Lighting: Ensure that the computer room is well-lit, with appropriate lighting levels to reduce eye strain. Avoid glare on the computer screens by using adjustable blinds or curtains.

  6. Regular Breaks: Encourage users to take regular breaks from prolonged computer use. Suggest the 20-20-20 rule: Every 20 minutes, look away from the screen at an object 20 feet away for at least 20 seconds.

  7. Stretching Exercises: Promote stretching exercises for the neck, shoulders, and back to help alleviate muscle tension and improve blood circulation. Display posters or provide resources on desk stretches and exercises.

  8. Correct Posture: Educate users about proper sitting posture, emphasizing the importance of maintaining a neutral spine position. Provide visual aids or ergonomic training materials to demonstrate the correct posture.

  9. Desk Organization: Encourage users to keep their workstations organized to minimize the need for reaching or straining. This includes keeping frequently used items within easy reach and arranging cables to prevent trip hazards.

  10. Individual Assessments: If the backache issue persists, consider offering individual ergonomic assessments for users. A specialist can evaluate the user's workstation setup and suggest personalized recommendations.

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When an image is inserted in a DTP document is selected, handles on its placeholders appear.  State three uses of these handles

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

 

Define the following

(a) Cookies

(b) Spyware

(c) Phishing

(d)Spam

(e) Pharming

 

 

(a) Cookies

  • Information that a website stores about a user on their hard disk; this enables
    the website to remember details about the user when they next visit the website.

(b) Spyware

  • Program installed on a PC to gather information about the user. It monitors
    every key press and relays the information back to the home base

(c) Phishing

  • Sending an email that claims to be from a legitimate company; the recipient is then directed to a bogus website where their personal details will be collected

(d)Spam

  • Junk/ (unsolicited) electronic mail advertising products and services sent to a general mailing list.

(e) Pharming

  • Malicious code installed on a PC or on a server. This code directs users to a
    a fraudulent website without their knowledge.
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State the function of a switch in a computer network

  • It transfers data signals from one node directly to another in the network without broadcasting
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List two types of disaster recovery tools.

  • online storage
  • incremental backup
  • full backup
  • RAID (level 0, 1, 10)
  • uninterruptible power supply (UPS)
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(b) Routers have an important role in how the internet functions.
  Describe how a router directs data on the internet.

  • Reads the data/packet to find the recipient's address 
  • Has physical connections to >=2 different networks
  • Holds a routing table
  • Stores information about (IP) addresses 
  • Keeps packets inside a network by not forwarding them 
  • Forwards data / directs/forwards/sends packets 
  • Chooses the most efficient path to the next node
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A computer game involves driving a racing car around a track. State which two modes of data processing  would be appropriate, justifying your answers

  • Real time  E.g. turning the wheel must turn the car immediately
  • On line - Otherwise system cannot be real time
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Describe each of the following types of program errors, using an example.

Syntax error

Logical error

Run-time error

Syntax error

  • An error in the source code of a program like pront("Hello, " + name) instead of print
  • These are errors that emanate from improper use of language rules such as spelling mistakes,improper use of variables and misuse of reserved words

Logical error

  • A mistake in a program's source code that results in incorrect or unexpected behaviour like if age == 65: print("Eligible for a discount.") instead of using if age >= 65: print("Eligible for a discount.")
  • These are errors that occur due to imperfect comparisons

Run-time error

  • An error which occurs when a program is asked to do something that it cannot, resulting in a ' crash'9. For example, asking a number to be divided by 0 such as 72/0.
  • An error that results in a sudden halt of an executing program

 

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The introduction of a new system involves evaluation and maintenance once the system is
implemented.
Describe the evaluation and maintenance stage of the systems development life cycle (SDLC)
and provide one example of an activity undertaken in this stage.

  • Continually monitoring, evaluating and updating the system once it is operational. Activities include rectifying bugs, requesting changes, updating aspects, finding errors, maintaining code etc.
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Computer Studies Paper 1 2021  KCSE Prediction Section B Qs. 17,18 and 19

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

Dept Code

Dept Name

001

Computer

002

Aviation

003

Engineering

 

Table 2

DeptID

Student Registration No.

Student’s Name

002

St01

Alex Too

003

St02

Naomi Komi

002

St03

Peter Kengo

 

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)

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What is utility software?

  • System software that analyses, configures, optimises and maintains a computer system
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State the role of an ISP.

  • To provide access to the Internet
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Programmers use trace tables with algorithms. Explain the purpose of a trace table.
It helps the programmer visualise the steps in a program / find errors/bugs / check the algorithm gives the correct output (1) because they can see the value a variable holds at a given point in an algorithm (1)
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