COMPUTER STUDIES PAPER 1 Marking Scheme - 2017 MURANG'A MOCK EXAMINATION

SECTION A 40 marks

1.  
   • Computer room should be well lit to avoid eye strain
   • avoid over bright wall paints that reflect too mush light causing eye strain
   • adjust brightness of the computer monitor until the eyes feel comfortable before using the computer
   • use/fit the monitor with radiation filter screens
   • avoid using flickering monitor
   • seat for the user must be comfortable and have a straight backrest that allows someone to sit upright
   • take frequent breaks while working with a computer
2.  
   1. insert
      • helps the user to insert or replace a character at the cursor position
   2. Delete
      • delete characters from the cursor position from left to right

3.  
   • setup a computer network
   • maintain and enforce security measures on the network
   • monitor the use of network resources
   • maintain and trouble shoot network related problems

4.  
   • be careful about body language, sitting arrangement, closeness etc
   • avoid personal biases in your questions and perceptions
   • interviewee must be informed in good time and topic communicated earlier

5.  
   1. Portability refers to whether a program can be copied or installed in more than one computer
   2.  
      • in-house developed programs
      • Venue at the-shelf software purchase through a vendor
      • Open source

6.  
   1. 10100­₂ 
   2. 1100.001₂ 
   3. 326.448₈

7.  
   • Entertainment – e.g. music, movie
   • Distribution of software
   • Archival storage

8.  
   1. NIC – a device that creates a physical link to the computer and the transmission media
   2.  
      • length
      • Modem converts a signal from digital to analog form for the purpose of transmission over the analog media
   3. receives a signal from one section of a network, clean it to remove any distortion, boosts it and sends it to another section

9.  
   • organize the main memory into blocks of sizes called partitions
   • assigns main memory storage partitions to data and instruction
   • Access to data is given using addressing the partition

10.  
    • hardware configuration
    • Basic design of the computer e.g. IBM, APPLE
    • Applications intended for the computer
    • User friendliness or HCI

11. Start                                       start
    Input                                      input
    pie = 3.14                               area = 3.14 *r*r
    area = pie*r*r                         print r, area
    print area                                     stop
    end
     

12.  
    1.  
       • one – to – one
       • one – to – many
       • many – to – many
    2.  
       • relationship based on primary and foreign keys
       • a feature that governs the nature of records in a one – to – many relationship between tables in database

13.  
    1.  
       • inbuilt fonts – extra fonts
       • prepare at work in commercial circles
       • a typesetter can create and edit very complex text and graphical objects
       • superior image handling capabilities such as brightness, cropping and resolution
    2. Cards, certificate, newspapers, magazines, pamphlets, newsletters, books, calendars

14.  
    1.  
       • creation
       • Transmission
       • Preparation
       • Media conversion
       • input validation
       • sorting
    2.  
       1. reference file – used for reference or lookup purposes that is required during processing
       2. Report file – used to store permanent records extracted from the master file or generated after processing operation

15.  
    1. Fraud – use of computer to conceal information or cheat other people with the intention of gaining money or information
    2. Alteration – the legal charging of data or information with the intention of misinforming authorized users or gaining

16.  
    1.  
       
    2.  
       • selection
       • sequence
    3. error detection methods
       • desk checking (dry-run) – going through the program while still on paper
       • using debugging utilities – enter the program editor where syntax errors are detected during translation
       • using test date – carries out trial runs
       • various data variations and extreme including good and bad data are entered to see how the program would handle them

17. 1. Advantages
       • immune to electro magnetic interference and ear dropping
       • fast and supports high band width
       • large distance can be covered because it has low attenuation
       • can be used in hazardous environment
       • smaller and lighter than copper
         
         disadvantages
       • connecting devices are expensive
       • installation is difficult
       • complex to configure
       • expensive/ difficult to repair
    2. Analog
       • made up of continuous varied wave form.
       • it is transmitted over telephone line.
       • a codec converts an analog signal to digital for transmission via a digital medium
         
         Digital signal
       • made up of non continuous discrete wave form
       • computers
       • a modem converts a digital signal to analog for transmission over the analog media
    3.  
       • thin net
       • Thick net
    4.  
       1. Microwave transmission consists of point to point transmissions meaning a signal is divided through a focused beam from transmitter to receiver while satellite is usually launched into speck
       2. Example of internet protocol 
          • ICPIP
          • TCP
          • IP
            
            
            
            
            
            
            

19.  
    1.  
       
    2.  
       1. A:/MEMO₂/Fraud
       2.  
          • do not drop the diskette down
          • don’t put heavy objects on top
          • don’t put near magnets
          • don’t remove from drive when still being read/written
       3. use of password
    3.  
       • I/O 
       • CPU
       • memory
       • secondary storage
       • communication & ports

20.  
    1. Direct approach
       • user simply stops using old system and starts using the new one
         
         Parallel approach
       • old and new system are operated side by side until the new system has shown it is reliable
         
         Phased approach
       • parts of a new system are phased in separately either at different times or all at one in groups
         
         Pilot approach
       • entire system is tried out but only by some users
    2.  
       1. Private data – belongs to an individual and must be accessed through direct permission from the owner Confidential data – held by government or organization about people but can be seen by authorized people only.
       2.  
          • fit strong metallic grills and locks to doors
          • don’t welcome strangers into the lab
          • install alarms
          • employ guards
          • burglar proof
    3.  
       1.  
          • output specification
          • input specification
          • file /data/tables
          • hard ware/soft ware
       2.  
          • cost benefit analysis
          • schedule 
          • Users
          • environment
          • technology