Computer Studies Paper 1 Questions and Answers - Lainaku II Joint Mock Examination 2023

INSTRUCTIONS TO CANDIDATES

• This paper consists of TWO sections: A and B
• Answer ALL the questions in section A
• Answer question 16 and any other THREE questions from section B
• Candidates should answer the questions in English.

SECTION A (40 MARKS)
ANSWER ALL QUESTIONS FROM THIS SECTION

1. Give FOUR characteristics of first generation computers? (2marks)
2.  
   1. Why are powder fire extinguishers not allowed in the computer room? (1 mark)
   2. What is the difference between delete and backspace keys? (2 marks)
3. Give FOUR factors that describe the ideal environment for a computer to work properly. (2marks)
4. Give TWO advantages of using sound output devices (2marks)
5. Give TWO application areas of OMR (2marks)
6.  
   1. Distinguish between primary and secondary storage devices. (2marks)
7. State FOUR devices that support multimedia capability on a computer (2marks)
   1. Differentiate between the terms: volatile memory and non-volatile memory. (2marks)
8. Differentiate between misreading and transposition errors in data processing (2marks)
9. What is the function of the power supply unit found in the system unit? (2marks)
10.  
    1. Name FOUR approaches that may be used to replace a Computerized Information system. (2marks)
    2. Which of the approaches named in (a) above is appropriate for critical systems? Explain. (2marks)
11. Terry intends to download a movie from the Internet. State the two factors that may determine the total time taken to complete the download. (2 Marks)
12. A lecturer keeps the following student details in a database: name, age, course.
    1. Write an expression you would use to compute the year of birth of a student using this year as the current year. (2 marks)
    2. What query expressions would the lecturer use to list the students whose age is above 15 years and below 25 years? (2 marks)
13.  
    1. Explain each of the following roles performed by an operating system
       1. Memory management ( 2 marks)
       2. Interrupt handling ( 2 marks)
14. A computer teacher has put a rule that flash disk should not be used in the computer laboratory
    1. Give a reason for the rule (1 mark)
    2. State two alternatives that can be used to achieve the same objective (1 marks)
15.  
    1. What is a utility software? (1 mark)
    2. Give FOUR examples of utility software (2 marks)

SECTION B (60 MKS)
Answer question 16 and any other 3 questions.

16.  
    1.  
       1. What is system maintenance? (2marks)
    2. Differentiate between absolute and relative cell referencing. (2marks)
    3. The formula $A$4 +C$5 is typed in cell D4 and copied to cell H6. Write down the formula as it would appear in cell H6. (2marks)
    4. Generate output for the following pseudo code (4marks)
            START
                      X= 5
                      WHILE (X<15) DO
                                 Y= X +2
                                 X=X+3
                                 PRINT X,Y
                       ENDWHILE
                       PRINT (“DONE’,X)
             STOP
    5. Draw a flowchart for the above pseudo code (5 marks)
17.  
    1. Using 10-bits binary number system, perform the following decimal operation using two’s complement. (4 marks)
       129₁₀ - 128₁₀
    2. Convert the following into binary 6CD₁₆ (2 marks)
    3. Perform the following binary arithmetic 11001.101+1110.011 (2 marks)
    4. Define the following terms. (3 marks)
       1. Record
       2. File
       3. Database
    5. List any FOUR ways of dealing with a virus on a computer. (4 marks)
18.  
    1. Explain the functions performed by (2 marks)
       1. The control unit-
       2. Arithmetic and logic unit (ALU)
    2. Define the following terms in relation to computer software . (3 marks)
       1. Free ware.
       2. Proprietary
       3. Open source
    3.  
       1. Define the term E-commerce (2marks)
       2. List down TWO advantages of e- commerce as used in modern business environment (2marks)
    4. Describe THREE ways how computing has been applied to each of the following areas:
       1. Reservation systems. (3 marks)
       2. Law enforcement (3 marks)
19.  
    1. 1. Name any TWO types of non-printable guides in DTP. (1mark)
       2. Explain the functions of each of non-printable guides in (19 (a)i) above (4 marks)
    2. State FOUR factors to consider when designing a good file (2 marks)
    3. Name THREE responsibilities that are carried out by a:
       1. Web administrator ( 3 marks)
       2. Computer trainer (3 marks)
    4. Identify TWO disadvantages of Observation method used in fact-finding. (2 marks)
20.  
    1. List THREE advantages of wireless communication over wired communication. (3 marks)
    2. Using a Diagram, describe the following signals and state where each is applied in network communication:
       1. Analog; (2 marks)
       2. Digital. (2 marks)
    3. Name the TWO types of coaxial cables. (2 marks)
    4.  
       1. Define the term network protocol. (1 mark)
    5. List FOUR internet protocols (2 marks)
    6. Describe star topology as used in networking (3 marks)

MARKING SCHEME

1. Give four characteristics of first generation computers? (2marks)
   • Large in physical size
   • Used vacuum tubes
   • Produced a lot of heat.
   • Consumed a lot of power.
2.  
   1. Why are powder fire extinguishers not allowed in the computer room? (1 mark)
      • Powder particles settle on storage devices and may scratch them during read/write operation.
   2. What is the difference between delete and backspace keys? (2 marks)
      • Delete key erases characters from the cursor to the right while backspace erases characters from the cursor position to the left
3. Give four factors that describe the ideal environment for a computer to work properly. (2marks)
   • Free from dust
   • Free from dust water,
   • Free from dust magnets,
   • Well ventilated rooms,
   • Medium humidity, etc.
4. Give two advantages of using sound output devices (2marks)
   • No reading is necessary.
   • Useful in situations where you can’t look or where you are busy.
   • Fast, natural output.
   • People grow fond of “computer speak”.
5. Give two application areas of OMR (2marks)
   • Marking of Multiple choice exam.
   • Market research questionnaires.
   • Payroll data entry.
   • Traffic surveys.
6.  
   1. Distinguish between primary and secondary storage devices. (2marks)
      • Primary storage is accessed directly by CPU while secondary is not.
   2. Differentiate between the terms: volatile memory and non-volatile memory. (2marks)
      • Volatile memory is temporary while non-volatile is permanent
7. State FOUR devices that support multimedia capability on a computer (2marks)
   • CD/ DVD drive
   • Sound card
   • Graphic adapter
   • USB ports
   • Monitor/ Screen
   • VGA/HDMI cables
8. Differentiate between misreading and transposition errors in data processing (2marks)
   • Misreading error occurs due to incorrect reading of data eg 509 being typed as S09while transposition errors occurs due to incorrect position of data captured eg 898 being typed as 889
9. What is the function of the power supply unit found in the system unit? (2marks)
   • Converts the alternating high voltage current (AC) into direct current (DC)
   • They also regulate the DC output voltage to the fine tolerances required for modern computing components.
10.  
    1. Name four approaches that may be used to replace a Computerized Information system. (2 marks)
       • Parallel,
       • Pilot,
       • Phased,
       • Direct / Straight
    2. Which of the approaches named in (a) above is appropriate for critical systems? Explain. (2 marks)
       • Parallel changeover (1 mark)
         Reason:
       • The system operations are not interrupted prior to the changeover in terms of time and quality of production. (1 mark)
11. Terry intends to download a movie from the Internet. State the two factors that may determine the total time taken to complete the download. (2 Marks)
    • 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
12. A lecturer keeps the following student details in a database: name, age, course.
    1. Write an expression you would use to compute the year of birth of a student using this year as the current year. (2 marks)
       YOB:2008 – [Age] while taking 2023 as the current year or
       = Year(Now) – Age or = Now() – age
       = Now(yyyy) – Age or = Date(yyyy) – age (2 marks)
    2. What query expressions would the lecturer use to list the students whose age is above 15 years and below 25 years? (2 marks)
       • Typing
         >15AND <25 or Between 15 and 25 or If((age <25) and (Age>15)) in the criteria row of the query
13.  
    1. Explain each of the following roles performed by an operating system ( 2 marks)
       1. Memory management
          • Programs must be loaded into memory before they can be executed, and moved out of memory when they are no longer required. An Interrupt is a break from the normal sequential processing of instructions in a program.
       2. Interrupt handling
          • Each hardware device communicates to the processor using a special number called the Interrupt Request number (IRQ). Therefore, when an interrupt occurs, control is passed to the Kernel, which determines the cause of the interrupt. The processor stops executing the current program to wait for the corrective response of the user. Control is returned to the program that was interrupted once corrective action has been taken
14.  A computer teacher has put a rule that diskettes should not be used in the computer laboratory
    1. Give a reason for the rule (1 mark)
       • To prevent the spread of viruses between the computers
       • To prevent unauthorized copying of programs from or to the computers
       • Students may carry immoral files using the diskettes
    2. State two alternatives that can be used to achieve the same objective (1 marks)
       • Using diskless computers
       • Use of antivirus software to detect/ clean viruses before use
15.  
    1. What is a utility software? (1 mark)
       • This is a program used frequently by the computer to carry out routine jobs Utility software is used to manage computer files, diagnose and repair computer problems and assist in helping the computer to run more efficiently.
    2. Give four examples of utility software (2 marks)
       • Text editors
       • Sort utility
       • Language translators
       • Merge utility
       • Loader
       • Copy utility
       • Linker
       • Dump utility
       • Diagnostic tools
       • Database management
       • system

SECTION B (60 MKS)
Answer question 16 and any other 3 questions.

16.  
    1.  
       1. What is system maintenance? (2marks)
          • Adjustments and enhancement of requirements or correction of errors after the system has been implemented
    2. Differentiate between absolute and relative cell referencing. (2marks)
       • Absolute referencing is a method of referring to a cell such that constant values can be copied across a group of cells this reference always refers to cells in a specific location of the worksheet cell if they are copied from one cell to another while Relative cell referencing is a method of referring to a cell such as that a formula copied a cross a group of cells changes relative to position of each cell into which it is copied.
    3. The formula $A$4 +C$5 is typed in cell D4 and copied to cell H6. Write down the formula as it would appear in cell H6. (2marks)
       • =$A$4+G$5
    4. Generate output for the following pseudo code (4marks)
                START
                 X= 5
                 WHILE (X<15) DO
                  Y= X +2
                 X=X+3
                PRINT X,Y
          ENDWHILE
          PRINT (“DONE’,X)
       STOP
       a) OUTPUT ½ mark each
       

       X	Y
       8	7
       11	10
       14	13
       Done 17	15

    5. Draw a flowchart for the above pseudo code (5 marks)
       
       • Award 1 mark for correct flow of logic
17.  
    1. Using 10-bits binary number system, perform the following decimal operation using two’s complement. (4 marks)
       129₁₀ - 128₁₀
       
       +129 = 00 1000 0001 (1 mark)
       128 = 00 1000 0000 (1 mark)
       −128 = 11 0111 1111 (ones complement)
                                   +1
                   11 1000 0000 (Twos complement) (1 mark)
       129− 128
            00 1000 0001
       + 11 1000 0000
         100 0000 0001 (1 mark)
       Hence = 00 0000 0001₂ or 1₂ (the overflow bit is ignored)
    2.  
       1. Convert the following into binary 6CD₁₆ (2 marks)
          6 = 0110
          C = 1100
          D= 1101
                          6CD₁₆ = 011011001101₂ (award ½ mark for each conversion)
       2. 11001.101+ 1110.011=101000.000 (2 marks)
    3. Define the following terms. (3 marks)
       1. Record - A collection of related fields that represent a single entity.
       2. File - A collection of related records in a database
       3. Database - Holds all related files or tables forming the highest data organization hierarchy
    4.  
       1. List any four ways of dealing with a virus on a computer. (4 marks)
          • Run anti- virus programs frequently
          • Limit the sharing of secondary storage devices.
          • Always install up-to-date anti-virus programs to your computer.
          • Always scan all downloads while using the internet
          • Do not run applications/programs from unknown sources
18.  
    1.  Explain the functions performed by (2 marks)
       1. The control unit-
          • Co-ordinates all processing activities in the CPU as well as input, storage and output operation
          • Determines which operation is to be executed
       2. Arithmetic and logic unit (ALU)
          • Performs al arithmetic and logic operations
    2. Define the following terms in relation to computer software . (3 marks)
       1. Free ware.
          • Software products that are freely made available to the use.
       2. Proprietary
          • Those are software whose source code is hidden for users.
       3. Open source
          • These are software whose source code is available to the user and are encouraged to modify, distribute and use.
    3.  
       1. Define the term E-commerce (2marks)
          • E-commerce is a way of doing business where the transactions are carried out electronically without the seller and buyer interacting physically.
       2. List down two advantages of e- commerce as used in modern business environment (2marks)
          • Reduces traveling, hence saves money and time
          • A company can access customers all over the world, and is not limited by space & wagons
          • Reduces operating costs of small business as they can establish websites where they can auction their good & services. This also increases their sales.
    4. Describe THREE ways how computing has been applied to each of the following areas:
       1. Reservation systems. (3 marks)
          • To keep record of reservation
          • For online reservation (i.e. provide online remote services)
          • Paperless transaction (Paying via credit cards)
          • Easy to check for vacant positions
          • Preparation of the payroll for their employees
       2. Law enforcement (3 marks)
          • For keeping record on fingerprints
          • Biometric analysis in crime detection so as to provide immediate & accurate information
          • Scene monitoring & analysis to help the police in arresting traffic offenders and criminals
          • Preparation of the payroll for their employees
19.  
    1.  
       1. Name any TWO types of non-printable guides in DTP. (1mark)
          • Ruler guides.
          • Column guides.
          • Margin guides.
       2. Explain the functions of each of non-printable guides in (11) (a) above (4 marks)
          • Ruler guides: Lines that are used to align text and graphics in the correct position on printable area or the paste board.
          • Column guides: helps to divide a given page into a number of columns e.g. as used in a newspaper.
          • Margin guides: They define the printable area such that any text or graphics outside the margin guides will not be printed.
    2. State FOUR factors to consider when designing a good file (2 marks)
       • Record key field: - this is usually an attribute that is unique for each record.
       • Data type for each field: - each field has a data type. In a database, the data type of book titles can be stored as ‘Text’, while the Date of borrowing a book can be stored as ‘Date/Time’.
       • Length of each field: - a field used to store names can be specified to be 30 characters long, while a field used to store numbers/integers can be specified to be 10 characters long.
       • Backup and recovery strategies: - the updated copies of data & information files need to be stored in a different place other than the location of the current system. This ensures that, if the current file gets corrupted, the backed up data can be used to recover/reconstruct the original file.   (A ward ½ x4=2marks)
    3. Name THREE responsibilities that are carried out by a:
       1. Web administrator ( 3 marks)
          • Develop & test websites
          • Maintains, updates & modifies information on the websites to meet new demands by the users.
          • Monitors the access & use of internet connection by enforcing security measures
          • Downwards information needed by an organization or institution from internet websites
       2. Computer trainer (3 marks)
          • Training people on how to use a computer & the various application programs
          • Development training reference materials
          • Guiding learners on how to acquire knowledge through carrying out research
          • Advising the learners on the best career opportunities in the broad field of ICT
          • Preparing learners for ICT examinations
       3. Identify two disadvantages of Observation method used in fact-finding. (2 marks)
          • The person being observed may perform differently or change his/her behaviour leading to wrong requirements being observed
          • The work being observed may not involve the level of difficulty or volume normally experienced during that period of time.
          • The need to be on the site where the activities are taking place consumes a lot of time.
          • Some activities may take place at odd times causing a scheduling inconvenience for the analyst.
20.  
    1. List three advantages of wireless communication over wired communication. (6 marks)
       Advantages
       • More flexible in operation as compared to bounded i.e. A user can move around with a wireless gadget
       • Can cover areas where laying infrastructure would be a challenge
       • Can cover large geographical areas
         Disadvantages
       • Security issues – easy to hack, eavesdrop etc as compared to bound.
       • The initial cost is very high due to certain infrastructure
       • Can be impaired by a number of factors like, rain, current etc as compared to bound
    2. Describe the following signals and state where each is applied in network communication: (4 marks)
       1. Analog;
          • Continues signal/ waveform in nature widely used in radio broadcasting
       2. Digital.
          • Discrete in nature/operates in the series of 1s and 0s widely used in wireless broadcasting e.g Dstv
            NB
            
            Accept illustrations and award full marks
    3. Name the two types of coaxial cables. (2 marks)
       • Thinnet coaxial cable also known as 10BASE2
       • Thicknet coaxial cables also known as 10BASE5 No description required for this question
    4.  
       1. Define the term network protocol. (1 mark)
          • The set rules and procedures that govern communication between two different devices or computers
    5. List four internet protocols (2 marks)
       • Hypertext Transmission Protocol - HTTP
       • Transport Control Protocol - TCP
       • Internet Protocol Simple Mail Transfer Protocol - SMTP
       • File Transfer Protocol
       • Internet Control Message protocol - ICMP User Datagram Protocol - UDP
       • Post Office Protocol - POP
    6.  Describe the star topology as used in networking (3 marks)
       • Star topology – in this topology, all devices are connected to a central hub. Workstations communicates across the network by passing data through the hub. When the hub receives data from a transmitting computer, it broadcasts the message to all the other workstations on the network.