Computer Studies Paper 1 Questions and Answers - KCSE 2021 Past Papers

 Ways in which computers are used in health care.

• Telemedicine: A doctor can use a computer to treat a patient who is in a remote location (or the doctor could be in a remote location)
• Data analysis: Performing laboratory analysis and to match samples Communication: Computer network media are used to facilitate communication between stake holders in the health industry.
• Dedicated computers: Health care equipment embedded with computers used to perform special functions
• Security: computerized devices are used to provide surveillance of a health centre
• Computers support hospital information management system that help to make accurate decisions
• Medical Imaging: a high resolution image generation of human body
                                                                                                        First 2x1

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 Website

• A group of related web documents stored in a web server and linked together such that a user can jump from one section of a document to another section or to another file.
  NB: Web page/Internet page/virtual space                                         2 or 0

 2

 Reasons for enactment data protection laws by a government

• The government being compelled to protect individual and organizational fundamental rights to personal information.
• To safe guard privacy

 2

 Cell Formats

1. 9022 111 000 - Custom format /Autonumber/Number/General  (1 mark)
2. 31/10/2022 - Date
                         Date/Time or Value                                               (1 mark)

 2

 Uses of image handles

• Resizing the image
• Increasing the image
• Decreasing the mage
• Rotating the image
• Tilting the image
• Stretching the image
• Changing shape
• Moving the image
• Flipping over the image
                                                                                                       First 3 x 1

 3

 Circumstance under which dry-run testing is performed.

• When there is a need to identify manually the logic flaws in a program by using sample data to trace through it.
  NB: To check for error
• To check if program is working 
• Manual running of program                                                             2 or 0

 2

 Ways in which data validation is implemented on an input form.

• Using displayed comments to guide/alert a user.
• Using controls which restrict the type of data to be entered. 
• Using error triggers to alert a user when wrong data is entered.
• Using appropriate data type during the design of the table.
  NB. Mark restricting points e.g. Data types, input masks, primary key, list boxes, field size, validation rules, required, lookups, format, caption, default value,                                                                                First 2 x 1

 2

 Roles of a computer trainer in an organization.

• Train workers to use computers hardware and software
• Develop training materials
• Evaluate learning outcomes
• Establish learning needs 
• Provide user support
  NB: Look for evidence of training                                                     First 3x1

 3

 Electronic data processing modes

• Real time processing
• On-line processing
• Time-sharing processing
• Distributed processing
• Batch processing/Offline
• Multiprocessing
• Multiprogramming

4

 Features of a GUI operating system.

1. Pointer
   • It is a symbol that appears on the display screen which is moved using pointing devices in order to select an object or a command.
     NB. Accept device name/definition of pointing device   (2 marks)
2. Desktop
   • It is the area on the display screen where icons representing different programs are placed.
     NB. Allow Starting point/first screen/welcome screen/homepage 
     (2 marks)

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Circumstances under which the following input devices are used

1. Optical Character Reader
   
   • Used when the text on a paper is to be instantly converted to machine readable formats.
     NB. Allow evidence of direct capture/scan including examples of usage e.g. stick control                                                          (1mark)
2. Optical Mark Reader
   Used when some detailed marks on a paper are to be recognized in a computer formats.
   NB. Allow evidence of usage in Marking multiple choice questions, lottery
   tickets etc                                                                                         (1mark)

 2

  Characteristics of an impact printer

• Produces noise while printing
• There is physical contact with
• paper/striking
• Has low consumable costs
• Useful for bulk printing
• Can print multipart copies
• Has few colours
• Low quality printouts/mono chrome
• Is a character printer
• Has slow printing speed
• Has low resolution
• Has few fonts/limited fonts
• Has one size of font size
• Has poor graphics 
• Has one type of font style

 3

 Features of a Word Processor:

1. Hyphenation
   • It is a feature which allows a word to break lines between the syllables in order to have uniform spacing between words.
     NB. Accept illustrations                                                      (2 marks)
2. Status bar
   • It is the area at the bottom of word processing screen that can be made to display options such as page, number, word count, permission etc.
     NB. Allow strip used for communication purposes
     Displays currently running tasks                                          (2 marks)

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1.  
   1.  
      1. - First Generation (1 GL)/Machine level/low level 1 mark
      2. - Fourth Generation (4 GL)/High level/SQL 1 mark
   2.  
      1. - Advantages of First Generation (1 GL)
         • They are translation free
         • Can be directly executed by a computer
         • Programs written are executed very first
         • Programs written are executed efficiently by the CPU
         • The program written utilize the memory in an efficient manner because it is possible to keep track of each bit of data.
         • Stable/Hardly crashes                                                First 2 x 1
      2. - Advantages of Fourth Generation (4 GL)
         • The program are machine independent/Portable 
         • The program are easy to learn
         • Easy to understand
         • The languages provides better communication   First 2 x 1
2. Pseudocode
   Start
   Input TotalEmployee
   Count=0
   
   While count TotalEmployee
          Input Employee salary
          If salary > 70,000then
               Increment = 5/100 x Employee salary
          Else if Employee salary> 50,000 Then
               Increment = 8/100 x Salary
          Else
               Increment = 10/100 × Salary
           End if
          New salary = Salary + Increment
          Count = Count +1
          Print Employee salary
          Print Increment
          Print New Salary
   End while
   Stop
   Accept the correct use of any other loop construct
   
   Marks award guide
   Start/Stop 1
   Input No of Employee 1
   Decision (accept any two correct decision 2
   Computing new salary (Salary+Increment) - any one increment 1
   Looping - any evidence of looping 1
   Output 1
   Calculating New increment 1
   Logic 1
   

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1. Differences between Octal and Binary number system.
          Octal
   • Uses eight digits 0, 1, 2, 3, 4,5,6 and 7
   • The maximum value of a single digit is 7
   • Each position in a octal represents a specific power of 8
   • Uses less number of digits to represent a number
   • is base 8
   • A digit is represented by three bits                                           Any 2 x 1
     Binary
   • Uses two digits 0 and 1
   • The maximum value of a single digit is 1
   • Each position in a binary represents a specific power of 2
   • Uses more number of digits (bits) to represent a number
   • is base 2
   • each digit is represented by 1 bit
     NB. One difference is enough for 4 marks
     Correct one sided fact award 2 marks                                     0, 2 OR 4
2. 
   23₁₀ − 17₁₀ (Using 8-bits one's complement)
   Converting to bits
                  23₁₀ = 00010111₂
                  17₁₀ = 00010001₂  (1 mark)
   One's complement (17)
                                 =11101110 (1 mark)
             Adding to 23 +00010111
                                   100000101 (1 mark)
                                                + 1
                     Answer     00000110 (1 mark)
   NB. If eight bits have not been used then award a maximum of 3 marks
3. Ways in which a graphic designer would use a computer
   • Use the computer to take photos to be inserted in the design
   • Use a graphics program to design graphics
   • Use a computer and a scanner to directly capture images
   • Use a computer to source graphics from the internet
     NB. There should be evidence of working with graphics design
                                                                                                        First 4 x 1
4. The Operating System could perform each of the following disk management
   
   • Disk formatting: preparing a disk to store data
   • Disk partitioning: Creating a logical storage block in a disk/Scan disk/Check disk
   • Defragmentation: rearranging scattered related data in order to consolidate on the used space
   • Disk diagnostics: establishing the health status of a disk
     disk compression: Compact data space so as to create extra space
   • Data backup:
   • Creating a copy of original data
   • Virus/malware scan,
   • Creating a startup disk
   • Disk cleanup    First 3 x 1

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 3

1. Benefits a car selling company gains from e-commerce
   • Accessibility: the clients would be able to access the services from any part of the world.
   • Compliance with health requirement of social distancing hence reducing the risks of infections within the company.
   • The business would be conducted 24/7 from any parts of the world
   • Analysis of customer preference can easily made hence tailoring the
   • Analysis of customer behaviour so as to be able to easily predict the outcome of any event
   • Use the internet media to easily communicate with the customers
   • Sales campaigns can easily be run on the platform to attract more clients.
     NB. Look for enhancement to the company
     (Accuracy, Speed, Security, Ease, Accessibility, Reliability)
                                                                                                   First 3 x 2
2. Reasons why a system analyst would consider studying an existing system
   • In order to understand the organizational structure.
   • To determine the sources of data in the organization.
   • To establish the flow of data within the organization.
   • Accuracy and timelines aspect of the data handling process.
   • To establish the data storage mechanism.
   • To identify the type of data processing used.
   • To identify the reports being generated at various stages.
   • To establish user requirements.
     NB. Check for challenges/problems and user requirements
     Also ensure the candidates answer is in respect of the current system
                                                                                           First 5 x 1
     Usability testing  is mainly concerned with the ease in which a user could use the application
     NB. User friendly                                                                (2 marks)
     
     Functional Testing - is concerned with establishing whether the system is meeting its objectives.
     Workability of the system/performace                                 (2 marks)

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 4

1.  Purpose of each odf the following features in a spreadsheet chart.
   1. Legend
      • It is a brief description of data in the chart alongside each data items.
        Accept the term KEY
        Accept illustrations                   (2 marks)
   2. Data series
      • It is the collection of data points which corresponds to the data within a single row.
        Look for evidence of data used to plot chart
   3. Data marker
      • It is a symbol on the chart that represents a single value in the worksheet.
        Look for evidence of value/symbol on the chart representing values
                                                                                  (2 marks)
2. Challenges that a school may experience after installing a computer network
   • Cost of installation: the school will be reeling from the expenses asociated with the installation of the network
   • Maintenance cost:The school would ahve to incur extra expenses to ensure that the network is fucntioning as intended. Thsi includes hiring a personnel to manage it.
   • Security for personal and school data from getting into the wrong hands.
   • Malicious software would easily spread from one computer to another through the network.
   • Extra measures would be require to control access to information.
     Guiding points are 
     1. Costs
     2. Security
     3. Social ethics
     4. Skills
        NB; Accept any network related problem. e.g attenuation, server failure e.t.c                                                     First 3 x2 
3. Factors to consider when selecting the media for connectivity.
   • Cost: the cost of acquiring, installation and maintenance of the network.
   • Transmission distance - twisted pair, infrared and radio transmit only for short distance. Fiber optics can transmit for long distance.
   • Security: how data on transit
   • Security of media.
   • Error rate: the degree of susceptibility to interference by external factors such as magnetism.
     Additional points
     NB. Accept points on authenticity, warranty, ease of handling, compatibility, system requirements, upgradability, portability, user needs, user friendliness                                       First 3 x2 

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 3

1. Functions of the following network protocols
   1. SMTP - Simple Mail Transfer Protocol
      
      • It is used to transfer email over the network or internet. (1 mark)
   2. FTP - File Transfer Protocol
      
      • It is used to upload and download the files over a network (1 mark)
   3. DNS
      
      • It is used to resolve domain name to the IP address and vice versa. (1 mark)
2.  
   1. Characteristics of mesh topology
      
      • Every node in the network is connected to every other nodes/Point to Point
      • It is used in Wide Area Network to interconnect Local Area Networks
      • It is reliable since there are several routes to pass data
      • Failure of a node does not affect the network
      • Failure of a media does not affect the network
      • It is reliable
      • Uses many cable connections
        NB. Accept illustration of mesh topology that is correctly labelled
                                                                                             First 2 x 1
   2. Characteristics of Ring topology
      
      • Devices a Pagerin 10 ed in 15 losed loop +
      • All devices have equal access to media.
      • Devices waits for its turn to transmit data.                      First 2 x 1
3. Centralised Computing
   • It is a network design where processing is centralized and dumb terminals are used to request services from a mainframe. The mainframe is used to store all the data
     
                                                                                     Description @2
                                                                                     Drawing @2
     
     
4. Security threats:
   1. Social engineering
      • It is a technique used by a hacker to steal data by using psychological manipulation combine with social scene.
      • Act of soliciting for software information from unsuspecting user
                                                                                                  (2 marks)
   2. Vulnerability
      • It is a weakness, design problem or implemenation error in a system that can lead to unexpected or undesirable event regarding security system.
      • These are weak access points                                           (2 marks)

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