Computer Studies Paper 1 Questions and Answers - Nyeri Mocks 2021 Exams

Instruction to candidates

1. This paper consists of two sections A and B.
2. Answer all the questions in section A.
3. Answer question 16 and any other three questions from section B.
4.  All answers should be written in the space provided in the question paper.
5. Candidates should answer the questions in English.

For Examiner’s Use Only

QUESTIONS

SECTION A (40 MARKS)
Answer ALL questions in the spaces provided

1. Differentiate between embedded computer and dedicated computer (2 marks)
2. The current monitor technology uses LED back lit technology. Give two advantages of using TFT monitors over CRT monitors (2 marks)
3. A Form four student wants to send a large document to a printer.
   1. State the name for the area of memory that the document is sent to immediately from RAM. (1 mark)
   2. As the printer runs out of paper during printing, the operating system sends a signal back to the computer to stop temporarily. Name this function of the operating system (1 mark)
4.                        
   1. Differentiate between a flash memory and compact disk as used in computer storage devices. (2 marks)
   2. People like using DVDs overcompact disks yet they are of the same physical size. State threereasons that justifies this. (3 marks)
5. For a monitor to display images, it must be connected through video port to a video adapter or controller mounted on the mother board. What is the role of a video adapter? (2 marks)
6. Name four categories of input devices (2 marks)
7. State any two physical measures taken to protect a computer laboratory from unauthorized access. (2 marks)
8.  Most word processors have some automated features such as word wrap and type over modes. Describe these features (2 marks)
9. Differentiate between proofreading and formatting a document as used in word processing (2 marks)
10. Most computerized systems in different organizations face a lot of unauthorized access such as Eavesdropping, Surveillanceand Industrial espionage. State a control measure against each vice. (3 marks)
11. A world wide web is a vast virtual space in the internet where information is made available such as web portals and blogs. Different between a web portal and a blog. (2 marks)
12. Differentiate between filtering and hiding of rows/columns as used in spreadsheets (2 marks)
13. Industrial plants use computer systems in different ways such as Computer Aided design, manufacturing, Simulation and process control. Explain how computers are used in the mentioned areas above. (4 marks)
14.                              
    1. Differentiate between Job displacement and Job replacement. (2 marks)
    2. State three advantages of using automated production in manufacturing plants. (3 marks)
15. Due to high demand and dynamic nature of computers and information systems, there is need for qualified computer trainers. What are the roles of computer trainers? (3 marks)

SECTION B (60 MARKS)
Answer question 16 (compulsory) and any other THREE questions from this section.

16.                        
    1. By use of a Flowchart construct, differentiate between a while loop and FOR loop (4 marks)
    2. Study this flowchart and use it to answer the questions that follow
       
    3. Give the expected output from the flowchart when the value of Y is: (4 marks)
       1. 48
       2. 800
    4. Write the pseudocode that can be used to create a program represented by the above flowchart. (7 marks)
17.                          
    1. Differentiate between a primary key and a foreign key as used in databases. (2 marks)
    2. State four factors to be considered when designing a good database (4 marks)
    3. Explain the use of each of the following field datatypes as used in database (3 marks)
       1. OLE object
       2. Lookup wizard
       3. Memo
    4. Kibet has been experiencing a lot of problems in his computer. As a result, he decided to format his computer and re-installed a new operating system.
       1. What is formatting in relation to the above context (2 marks)
       2. What precaution must Kibet observe before formatting his computer (1 mark)
    5. You are required to purchase an operating system. State three factors that you should consider before acquiring the software. (3 marks)
18.                
    1. Define the following terms as used in networking (3 marks)
       1. Broadband
       2. Bandwidth
       3. Multiplexing
    2. List four elements of networking (2 marks)
    3.                    
    4. Most institutions are moving towards the use of fibre optic cables. State three reasons why fibre optic is preferred (3marks)
    5. Differentiate between Hub and Bridge as used in networking. (2 marks)
    6. The diagram below represents a signal transmission from point A to point E. Name the parts labeled A, B, C, D, E (5 marks)
       
19.                  
    1. Binary systems have been used to develop most electronic devices. Give three advantages of using binary. (3 marks)
    2. Convert the following number systems (4 marks)
       1. 37.625₁₀ to binary
       2. BCD.EF₁₆ to Octal
    3. Using twos complement, perform the following arithmetic operation leaving your answer in decimal notation. (4 marks)
       39₁₀ – 19₁₀
    4. A student was developing a file. List any four attributes that the operating system will assign the file (2 marks)
20.                              
    1. A system analyst in Changamwe preferred using phased changeover to implement a new system. State three reasons for this preference. (3 marks)
    2. State three reasons why an organization may change an information system. (3 marks)
    3. Different students were asked to state the characteristics of a system. The responses were:
       1. They are holistic
       2. They are open or closed systems
       3. They have a boundary and environment.
          Explain each of the above responses. (3 marks)
    4. Explain the following data collection stages as used in data processing (3 marks)
       1. Data preparation
       2. Media conversion
       3. Input validation
    5. State three ways a data entry clerk may use to reduce threats to data integrity (3 marks)

MARKING SCHEME

1. Differentiate between embedded computer and dedicated computer (2 mrks)
   • Embedded computers are special purpose computer used inside another device and usually dedicated to specific functions.
   • Dedicated computer is a general purpose computer designed to perform a specific task.
2. The current monitor technology use LED back lit technology. Give two advantages of using TFT monitors over CRT monitors (2 mrks)
   • Images formed in TFT do not suffer from angle distortion
   • TFT have low power consumption than CRT
   • TFT have a higher resolution than CRT
3. A Form four student wants to send a large document to a printer.
   1. State the name for the area of memory that the document is sent to immediately from RAM(2 mrk)
      • Input buffer
   2. As the printer runs out of paper during printing, the operating system sends a signal back to the computer to stop temporarily. Name this function of the operating system (1 mrk)
      • Interrupt handling
4.                      
   1. Differentiate between a flash memory and compact disk as used in computer storage devices (2 mrks)
      

      Flash memory	Compact disk
      Solid state device	Optical media
      Plugs directly to the USB port	Requires a disk drive
      Fast access of data	Slow access of data
      Uses circuitry access	Has moveable read and write head

   2. People like using a DVD over a compact disk yet they are of the same physical size, state three reasons that justifies this (3 mrks)
      • A DVD has a higher storage capacity
      • A DVD offers a better sound and picture quality than a CD
5. For a monitor to display images, it must be connected through video port to a video adapter or controller mounted on the mother board. What is the role of a video adapter (2 mrks)
   • It determines the resolution and clarity of the monitor
6. Name four categories of input devices (2 mrks)
   • Keying in devices
   • Pointing devices
   • Scanning devices
   • Automated method
7. Name any two physical measures taken to protect a computer lab from unauthorized access.(2 mrks)
   • Burglar proofing the room
   • Use of alarms
   • Use of padlocks
   • Use of special cards
   • Employing security guards
8. Most word processors have some automated features such as word wrap and type over modes. Describe these features (2 mrks)
   • A wordwrap is a feature that enables the cursor to move automatically to the start of a new line/page
   • Type over mode (overwrite mode) enables the user to edit an individual character of a word in a text document
9. Differentiate between proofreading and formatting a document as used in word processing (2 mrks)
   • Proofreading is the process of checking whether the document has typographical or grammatical errors
   • Formatting a document refers to enhancing the appearance of a document to be attractive and appealing to the eye of the reader
10. Most computerized systems in different organizations face a lot of unauthorized access such as Eavesdropping, Surveillance and Industrial espionage. State a control measure against each vice (3 mrks)
    • Eavesdropping: refers to tapping or listening into a communication channels to get information
    • Surveillance: Refers to monitoring use of computer system and networks using background programs such as spyware and cookies
    • Industrial espionage: it involves spying on competitor to get information that can be used to cripple the competitor
11. A world wide web is a vast virtual space in the internet where information is made available such as web portals and blogs. Different between a web portal and a blog (2 mrks)
    • Web portal: it is a specialised websites that offer restricted services such as e-learning, searching, e-mail, and sports to registered user updates, financial news and links to selected websites.
    • Blog: It is a website that contains personal information which can easily be updated
12. Differentiate between filtering and hiding of rows/columns as used in spreadsheets (2 mrks)
    • Filtering is the process of finding and working with a subset of related worksheet.this will display only the rows that meet the condition or criteria specified.
    • Hiding columns: it the process of making a columnl not be shown on the display or printed when you print the worksheet. The column is not deleted.
13. Industrial plants use computer systems in different ways such as Computer Aided design, manufacturing, Simulation and process control. Explain how computers are used in the mentioned areas above (4 mrks)
    • Computer Aided design: it is an integrated system that allows products that have been designed using design application software
    • Simulation: it allows some activities that would otherwise be expensive and dangerous in real life to be put under test
    • Process control: it refers to the use of a computer system to control an ongoing physical process.
14.                    
    1. Differentiate between Job displacement and Job replacement (2 mrks)
       • Job replacement implies that the employees who are computer illiterate lose their jobs and replaced by computer literate people
       • Job displacement is where the computer illiterate workers are moved from a department with computers to another place which does not require computer literacy.
    2. State three advantages of using automated production in manufacturing plants (3 mrks)
       • Increased efficiency due to the balancing of workload and production capacity
       • Improved customer service
       • Efficient utilization of resources such as raw materials
15. Due to high demand and dynamic nature of computers and information systems, there is need for qualified computer trainers are required. What are the roles of computer trainers(3 mrks)
    • Training people on how to use a computer and various application programs
    • Developing training reference materials
    • Guide learners on how to acquire knowledge through carrying out research
    • Advising the learners on the best career opportunities in the field of ICT
    • Preparing learners for ICT examinations
16.                          
    1. By use of a Flowchart construct, differentiate between a while loop and Repeat… Until loop (4 mrks)
       
       
       
       • In the WHILE Loop, the condition is tested before the execution of statements while REPEAT loop statements are executed before the condition is tested
       • In WHILE loop, statements are executed until the condition becomes FALSE the you exit while in REPEAT loop, you exit when the statement is true
       • In WHILE loop,statements may exit without any statement being executed while in REPEAT loop atleast one execution of statements must be done
    2. Study this flowchart and use it to answer questions that follows
       
       
       1. Give the expected output from the flowchart when the value of Y is (4 marks)
          1. 48 S=1
             Y=4.8
          2. 800
             S=2
             Y=8
       2. Write the pseudocode that can be used to create a program represented by the above flowchart (7 marks)
          START
          S=1
          READ Y
          REPEAT
          Y=Y/10
          S=S+1
          UNTIL Y<10
          PRINT S
          STOP
17.                  
    1. Differentiate between a primary key and a foreign key as used in Database (2 mrks)
       • Primary key is a special index that enforces uniqueness in a table
       • Foreign key is a field in a table that matches the primary field in another table
    2. State four factors to be considered when designing a good database (4 mrks)
       • Carefully study the requirements of the user in order to define all the data inputs, outputs and relationships required
       • Design a draft database on the paper to determine the number of files or tables required
       • Divided the information into separate fields, records and tables to allow flexibility in manipulating the database
       • Define a field for each table that will be used to identify each record uniquely
       • Give the most important fields the first priority
       • Design data entry forms needed for the database
    3. Explain the use of each of the following field data types as used in database (3 mrks)
       1. OLE object
          1. It is used for storing graphical objects such as pictures
       2. Look up wizard
          1. It is a field displays the data as a drop down list so that the user can select the desired value from the list
       3. Memo
          1. It is a field in database that contain alphanumeric data and can accommodate a maximum of 32000 characters
    4. Kibet has been experiencing a lot of problems in his computer. As a result, he decided to format his computer and re-installed a new operating system.
       1. What is Formatting in relation to the above context (2 mrks)
          • It is the process of preparing a new storage media by imprinting empty sectors and tracts on the surface of the disk so that the operating system can recognize and make it accessible
       2. What precaution must kibet observe before formatting his computer (1 mrk)
          • Make a backup of all the documents to avoid losing them
    5. You are required to purchase an operating system. State three factors that you should consider before acquiring the software (3 mrks)
       • Hardware configuration
       • The type of computer in terms of of size and make
       • The application software intended for the computer
       • User-friendliness
       • Documenmtation available
       • Cost of the operating system
       • Reliability and security provided by the operating system
18.                      
    1. Define the following terms as used in networking (3 mrks
       1. Broadband
          • An analog signal sent over the transmission medium using a particular frequency
       2. Bandwidth
          • It is the maximum amount of data that a transmission medium can carry at any one time
       3. Multiplexing
          • It is the process of sending multiple data signals over the same medium
    2. List Four elements of networking (2 mrks)
       • data communication media
       • communication devices
       • networking software
       • data signals
    3. Most institutions are moving towards the use of Fibre optic cables. State three reasons why Fibre optic is preferred (3 mrks)
       • It is immune to interference and eavesdropping
       • It is fast and support high bandwidth
       • Large distance can be covered because it has low attenuation
       • Can be used in hazardous places (highly flammable) because they do not generate electrical signal it is smaller and lighter than the copper cable hence ideal for space limited situation
    4. Differentiate between a Hub and a Bridge as used in Networking (2 mrks)
       • A Hub is a component that connects computers on a network and is able to relay signals from one computer to another on the same network.
       • A Bridge selectively determines the appropriate network segment for which a message is meant for delivery through address filtering
19. The diagram below represents the a signal transmission from point A to point E. Name the parts labeled A, B, C, D, E (5 mrks)
    1. Binary systems has been used to develop most electronic devices. Give three advantages of using binary (3 mrks)
       • It is difficult to develop devices that can understand or process natural languages directly it is easier to develop electrical circuits based on binary ON/OFF
       • All forms of data can be represented in binary system format
       • Binary devices are more reliable
       • They became smaller in size
       • They use less energy
    2. Convert the following number systems (4 mrks)
       • 37.62510 to binary
         Using long division get the binary of 37₁₀ =100101₂
         get the binary of the decimal by multiplying repeatedly by two i.e 0.625₁₀=0.101₂
         Add the binary of the whole number and the decimal
         100101₂+0.101₂=100101.101₂
         

         HEXADECIMAL	B	C	D	E	F
         BINARY	1011	1100	1101	1110	1111

         Group In terms of three            101,111,001,101.111,011,110

         To octal 5715.7368
    3. Using twos complement, perform the following arithmetic opration leaving your answer in decimal notation (4 mrks)
       39₁₀ – 19₁₀
       • using long division get the binary of:
         39₁₀ = 100111₂
         19₁₀= 10011₂
         write the binary of 1910 in 8-bits 19₁₀= 00010011₂
         ones complement of the binary of 19₁₀=11101100
         twos complement ones complement =11101101
         add the binary of 39₁₀ to the twos complement of 19₁₀
         
         11101101
         +0100111
         (1)00010100 ignore the overflow
         (1x2⁴)+(1x2²)=20₁₀
    4. A MOKASA student was developing a file. List any four attributes that the student must consider in the development process (2 mrks)
       • Key field
       • The data type
       • The lenghth of each field
       • Back up and recovery strategies
20.            
    1. A system analyst in changamwe prefers using phased change over to implement a new system. State three reasons for this preference (3 mrks)
       • To enable the analyst to test the system in phases
       • The operations and results of both systems are compare and evaluated
       • Errors can be identified and corrected before the old system is abandoned
    2. State three reasons why an organization may change an information system (3 mrks)
       • New opportunities
       • Incase of problems in the current system
       • New directives
    3. Different students were asked to state the characteristics of a system. The responses were as follows:
       • They are holistic
       • They are open or closed systems
       • They have a boundary and environment.
    4. Explain each of the above responses (3 mrks)
       • Holistic system: the different components of a system are grouped together to make a whole
       • Open or Closed: open system receives input from and gives out to the environment and can adopt to changes in the environment.
       • Boundary and Environment: it is a space within which the component operates.
    5. Explain the following data collection stages as used in data processing (3 mrks)
       1. Data preparation
          • It is the process of converting data from source documents to machine readable format
       2. Media conversion
          • This is where the data is converted from one medium to another
       3. Input validation
          • It is the process taken during data entry to prevent wrong data from being processed by subjecting to validity checks
    6. State three ways a data entry clerk may use to reduce the threat to data integrity (3 mrks)
       • Back up data
       • Control access to data by enforcing security measures
       • Design user interfaces that minimizes chances of invalid data entry
       • Using error detection and correction software when transmitting data
       • Using devices that directly capture data from the source