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Q&A-KCSE Computer Studies Paper 1

There are security concerns associated with cloud storage.
(a) State one way in which providers of cloud storage could prevent security breaches by their own employees

 (b) Explain why data on networks is encrypted

(a) One from:

  • Background checks
  • Access control
  • Physical security
  • User policies

(b) To prevent unauthorised access (1) so that data remains confidential (1) by making it unintelligible (1) because it is scrambled (1)

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Explain each of the following function of an operating system

Job scheduling/Process scheduling                                                                                              (2mks)

  • Operating systems allocate tasks/processes/jobs to the CPU using priority and FIFO principle

 Memory management                                                                                                                  (2mks)

  • OS allocates and de-allocates memory spaces to processes loaded into the RAM
  • Swaps processes between main memory and virtual memory created in the secondary storage
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State three utility programs associated with the use of a hard drive. Explain the purpose of each the program

  • File handling - Copy/move/delete
  • Anti-virus software - To protect files from attack by a virus
  • Defragmentation - To keep files sensibly arranged on the hard drive
  • Format - To divide the surface of a drive into smaller areas to aid storage
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Describe why fibre optic cable would be used for the backbone of the network. (2 marks)

 

Describe how the firewalls can ensure the security of the EmergWA network.

 

Describe a transmission media that would work better in remote areas

The volunteers assisting in an emergency all wear personal protection equipment (PPE) that has an RFID tag sewn into the collar so that they can be tracked if they become lost in a remote location. Identify what RFID is and outline how it works. (3 marks)

  • Fibre optic cable would be used because it has a higher bandwidth, allowing faster communication in the main part of the network. It is also more secure as it cannot be tapped.
  • Firewalls filter the data in and out of a network. Each packet is examined against the filter rules and if a packet is flagged, it is dropped. Only data packets that satisfy the filter rules are allowed through the firewall, thus providing a layer of security for the network.
  • A satellite system would be better as it does not rely on wifi, cellular etc. It is not subject to interference and is reliable in remote conditions
  • Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder, a radio receiver and transmitter. When triggered by an electromagnetic interrogation pulse from a nearby RFID reader device, the tag transmits digital data, usually an identifying inventory number, back to the reader. This number can be used to track inventory goods..
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451/1

COMPUTER STUDIES

PAPER 1

THEORY

DECEMBER 2021

TIME: 2 HOURS

 

FORM TWO END OF TERM TWO 2O21 EXAM

451/1

COMPUTER STUDIES

PAPER 1

THEORY

TIME: 2½ HOURS

 

INSTRUCTIONS TO CANDIDATES:

  • Write your name and ADMISSION number in the spaces provided above.
  • Write the date of examination and sign in the spaces provided.
  • This paper consists of two sections.
  • Answer all the questions in section A.
  • Choose one topic to answer in section B
  • All answers must be written in the spaces provided in this question paper.
  1. SECTION A
  2.  Answer all questions in this section
  3. What is a computer?                                                                                                            1mks
  4. State three physical components that make up a computer                                                 3mks
  5. State the hardware technological differences between the second generation and third generation computers                                                                                                          2mks
  6. State and explain three characteristics of a computer                                                         3mks
  7. State the functions of the following special memories in a computer                                3mks
  8. Buffers
  9.  
  10. Registers
  11. Cache
  12.  
  13. Define the following as used in data representation in a computer                                  (5mks)
  14. Bit
  15.  
  16.  
  17. Byte
  18.  
  19.  
  20. Nibble
  21.  
  22.  
  23.  
  24. Word
  25.  
  26.  
  27.  
  28. Word-length
  29.  
  30.  
  31. State two reasons why a DVD is superior to a typical compact disk                               (2mks)
  32. State three advantages of flat panel monitors over cathode ray tube monitors                   3mks
  33. Explain the following terms as used in word processing                                                  3mks
  34. Section breaks
  35. Thesaurus
  36. Superscript
  37. State two advantages of  impact printers                                                                             2mks
  38. State the function of the following keys on the computer keyboard                                  3mks
  39. Enter key
  40. Insert key
  41. Delete key
  42. State the technology used by the following secondary devices to store data                      3mks
  43. Magnetic storage devices
  44. Solid state storage devices
  45. Optical storage devices
  46. State three reasons why an operating system is important in a computer                         3mks
  47. A typical computer’s main memory consists of both volatile and non-volatile memory.
  48. i)  Explain what is meant by the term volatile memory                                          (1mark)
  49. ii) What is normally stored in the non-volatile part of a computer’s main memory (1mark)
  50. Explain why having cache memory can improve the performance of the CPU         (2mks)
  51. What is a computer system?                                                                                           (1mk
  52. Give two differences between a solid state drive (SSD) and a hard disk drive (HDD)   2mks
  53. State three categories of software classified according User license agreement              (3mks)
  54. State two disadvantages of Random Access Memory                                                       (1mk)
  55.  
  56.  
  57. a) Explain the functions performed by the following components of a processor   (2 marks)
  58. Control unit
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KCSE 2021  Prediction Computer Studies Paper 1  Q.16 (c)

c) Distinguish between a source program and a compiler as used in computer programming. [2]

Source program is the original program in a high level language as written by the programmer while a compiler is a program translator that converts source program to object code.

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(ii) The organisation has chosen wireless connectivity over wired connectivity for its new office building. There is no significant difference in the cost of installing either.
Give three reasons why the organisation might prefer wireless connectivity.

May not have space for cables to be installed

Employees and visitors can move around the building without disconnecting

Adding new users just means giving out the SSID and password

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State advantages of star network topology

  • Easy to add nodes
  • Managed centrally
  • Fewer data collisions
  • A single node failure does not affect the rest of the network
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Explain the purpose of each of the following features of a spreadsheet chart (KCSE 2021, Q19 (a))

  • Legend
  • A data series

  • Data Marker

Legend

  • Legends are a small visual representation of the chart's data series to understand each without confusion.

A data series

  • is a row or column of numbers that are entered in a worksheet and plotted in your chart, such as a list of quarterly business profits
  • A group of related data points or markers that are plotted in charts and graphs

Data Marker

  • A symbol on the chart that represents a single value in the worksheet.
  • A column, dot, pie slice, or another symbol in the chart that represents a data value
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State the formatting features used in Ms Excel

  • Font Formatting:

    • Font Style: You can change the font style (e.g., Arial, Times New Roman) for cell content.
    • Font Size: Adjust the size of the text within cells.
    • Bold, Italic, and Underline: Apply these formatting options to emphasize text.
    • Font Color: Change the color of the text.
  • Cell Formatting:

    • Number Formats: Apply various number formats, such as currency, percentage, date, and time.
    • Cell Borders: Add or remove borders around cells or cell ranges.
    • Fill Color: Change the background color of cells.
    • Text Alignment: Control how text is aligned within cells (left, right, center, top, bottom).
    • Text Wrapping: Allow text to wrap within a cell if it's too long to fit in one line.
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Defining  blocking of text as used in  word processing

  • Refers to selecting a group of text eg word, sentence or even a paragraph in order to work with it as a whole
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An organisation that supplies audiobooks over the internet is moving into a new office building.
 (a) One reason for networking devices is to provide access to the internet.
  (i) Give two other reasons for connecting devices to networks.
 

  • Share peripherals/devices (e.g. printers, scanners)
  • Communicate (e.g. email, instant messaging, play games)
  • Share data (e.g. files/music/videos/backups on servers)
  • Deploy/update applications
     
     

Explain the Fetch – Execute cycle and provide an example of a Central Processing Unit (CPU) component for each stage of the cycle

The Fetch – Execute cycle is a sequence of actions, performed by the processor as it fetches
a program instruction from its memory, determines what the instruction wants to do and
carries out those actions. The stages of the cycle are provided below.

  • Fetch the instruction – the processor fetches the instruction from a memory address stored in a program counter and transfers the instruction, via a data bus, to an instruction register. At the end of the fetch operation, the counter points to the next instruction that will be read in the next cycle.
  • Decode the instruction – the processor decodes the instruction stored in the instruction register, including getting any operands required to complete the instruction.
  • Execute the instruction – the decoded instruction is executed.
  • Store the result – the result generated by the execute phase is stored in the main memory, and/or sent to an output device. The program counter is updated with feedback from the arithmetic logic unit (ALU), to a different address from which the next instruction will be fetched.
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Using an example, explain a difference between a primary key and a foreign key in a relational database.

A primary key is a table field that uniquely identifies each record and ensures that duplicate entries are not allowed

A foreign key is primary key of a parent table placed in a child table to ensure that any record added to a child table is related to the one in parent table.


A foreign key is a field (or a set of fields) in one table that refers to the primary key of another table. It is used to establish and enforce a link between the data in the two tables, ensuring referential integrity.

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Describe four features of the operating system when providing a graphical user interface on a personal computer. Give a suitable example of each feature.

  • Windows for example a word processing application and a spreadsheet
  • Menus, for example, allow the user to perform operations or run applications such as right-click to create a new folder  
  • Icons for example a picture of linked computers for networking
  • Pointers(mouse or touchscreen)  for example to select items/trigger events  
  • Shortcuts for example to frequently used applications for example having a shortcut to your mail client on your desktop
  • File navigation for example when searching the hard disc for a file/folder using a browser
  • copying / deleting / moving/sorting/naming/searching of files or folders for example copying of a file from the hard drive to a USB pen drive (File handling)
  • Desktop customisation for example changing the colours and background image
  • Copy and paste for example between applications e.g. copying a graph from a spreadsheet to a word processor
  • Error messages for example provide users with error/warning/help messages for example ‘printer out of paper’ 
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State two reasons for carrying out software updates

  • To get the latest features
  • To update security features
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List three electronic data processing modes used in computers

  • Realtime processing
  • Batch processing
  • Timesharing
  • multiprogramming
  • Online
  • Batch
  • Distributed
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State the role of an ISP.

  • To provide access to the Internet
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Explain why a developer, who is good at both low-level and high-level programming, would normally use high-level languages when writing programs.

  • High-level languages have built-in functions;
  • High-level languages have built-in libraries;
  • High-level languages have more support/help;
  • High-level languages have structures (such as selection and iteration);
  • High-level languages can be less machine-dependent/more portable;
  • It (usually) requires fewer lines of code to be written;
  • It is (usually) quicker to develop code in high-level languages;
  • It is easier to find mistakes in code;
  • The code is easier to maintain//understand;
  • It is easier to structure code in high-level languages;
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The website has a uniform resource locator (URL).
An example of a URL is given.
https://www.google.co.ke/index.html
Complete the table to identify the name of each section of the URL.

https :  protocol

google.co.ke: domain name

/index.html: webpage/file name

 

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