S.P.6 KCSE COMPUTER STUDIES PAPER 1 PAST QUESTIONS AND ANSWERS

SAMPLE PAPER 6

COMPUTER STUDIES PAPER 1

451/1

SECTION A (40 marks)

Answer all questions in this section

1. State three classifications of micro computers when classified according to size. (3mks)
2. Give three main advantages of using computers for data processing functions over other types of office and business equipments (3mks)
3. (a) What is disk partitioning? (2mks)

   (b) Give two reasons for partitioning a disk. (2mks)

4. Give a reason for each of the following hardware considerations when selecting a computer system (4mks)
   1. Processor speed.
   2. Warranty.
   3. Upgradeability and compatibility.
   4. Portability.
5. Outline the functions of the following utility software (3mks)
   1. Loaders.
   2. Debuggers.
   3. Linkers.
6. Draw a diagram to illustrate the following. (3mks)
   1. USB Port.
   2. Serial Port.
   3. Parallel Port.
7. A computer operator in your school wanted to print a document but the printer could not print yet the online light is on and the printer paper is correctly placed. Give the other possible reasons why the printing process failed. (2mks)
8. Differentiate between office and magnetic scanning techniques and give two example of each.

(4mks)

1. Explain what the following Dos commands achieve when executed.
   1. C: \ > DIR P *.EXE (1mk)
   2. A: \ > format (1mk)
2. List three main types of human computer interface (3mks)

 (i) ………………………………………………………………………………………………………………………………….

 (ii)………………………………………………………………………………………………………………………………..

 (iii)……………………………………………………………………………………………………………………………….

1. Define the following terms as used in word processing.
   1. Word wrap (1mk)
   2. Thesaurus (1mk)
2. What is telecommuting? (2mks)
3. 
   Differentiate the following terms
   1. Source program (1mk)
   2. Object code (1mk)
4. Define the following terms
   1. Data processing (1mk)
   2. Data processing cycle (1mk)
5. List any four factors to be considered when selecting software. (2mks)

 (i) ………………………………………………………………………………………………………………………………….

 (ii) ………………………………………………………………………………………………………………………………..

 (iii) ………………………………………………………………………………………………………………………………

 (iv) ………………………………………………………………………………………………………………………………..

SECTION B

Answer question 16 (compulsory) and any other three questions from this section.

1. You have been asked by a standard four mathematics teacher to generate a list of even numbers between 0 and 201.
   2. Write a pseudocode used to solve this problem. (6mks)
   3. Draw a flow chart for the program above. (5mks)
   4. List four data types used in structural programming. (4mks)
2. (a) Define the following programming terms. (4mks)
   1. Machine language.
   2. Translator.
   3. Outline the change over strategies that can be used to move from manual system to computerized system. (3mks)

 (i) ………………………………………………………………………………………………………………………………….

 (ii) ………………………………………………………………………………………………………………………………..

 (iii) ……………………………………………………………………………………………………………………………….

(c) (i) State the stage of program development where an interview is used. (2mks)

1. State two advantages and two disadvantages of using interviews at the stage in C(i) above.

Advantages

 (i) ………………………………………………………………………………………………………………………………….

 (ii) ………………………………………………………………………………………………………………………………..

 Disadvantages

 (i)…………………………………………………………………………………………………………………………………..

 (ii) ………………………………………………………………………………………………………………………………..

1. (a) What is an expert system? (2mks)

   (b) (i) What is a robot? (2mks)

   1. Outline any four advantages of using robots in industries over human beings. (4mks)

 (i) ………………………………………………………………………………………………………………………………….

 (ii) ………………………………………………………………………………………………………………………………..

 (iii) ……………………………………………………………………………………………………………………………….

 (iv) ………………………………………………………………………………………………………………………………..

(c) Explain the following career opportunities in computing.

1. Software Engineers (1mk)
2. Computer technician (1mk)
3. Computer programmer (1mk)
4. System analyst (1mk)
5. Give three main categories of higher learning where you can advance your computer skills after O-level.

 (i) ………………………………………………………………………………………………………………………………….

 (ii)…………………………………………………………………………………………………………………………………

 (iii) ……………………………………………………………………………………………………………………………….

19. (a) Differentiate between a formula and a function as used in Excel. (2mks)

(b) What is the effect of the following function?

COUNTIF (A5:D5,”orange”). (2mks)

1. The first column in the table below contains the formula stored in all C10 of a spreadsheet. Enter the formula as they would appear when copied to cell F15 of the same spreadsheet.

(3mks)

1. (i) Explain the concept of distributed databases. (2mks)
2. State two advantages of distributed databases. (2mks)

(e) Outline two uses of forms in database design. (2mks)

(f) List any two word processor software. (2mks)

20. (a) Indicate the method of file access for the following file organization methods. (2mks)

(b) Use one’s complement to calculate 11101₂ – 101₂ (4mks)

1. Convert 0.375₁₀ into binary notation. (2mks)
2. Define the term network topology. (2mks)

(e) List any four physical topologies in a network (3mks)

(f) Differentiate between Ethernet and Token Topology. (2mks)

MARKING SCHEME

SAMPLE PAPER 6

451/1

• • Desktop computer
  • Laptop computer
  • Palmtop computer / notebook. (3mks)
• • Computers process data faster
  • Computers are more accurate
  • Computers are more efficient. (3mks)
• • This is the process of dividing a large physical disk into two or more partitions called logical drives (1mk)
  • (i) The user may intend to install more than one operating system on the same disk.

    (ii) For purpose of backup on the same disk but different partitions.

• • A good computer must have high processor speed. (1mk)
  • It is important to understand the terms and conditions of after selling a product in case of failure or malfunction that is whether the seller is ready to provide after sales services. (1mk)
  • The best convention would be to buy a computer that can easily be upgraded to accommodate emergent technologies. (1mk)
  • Smaller computer enhances mobility. (1mk)
• • Help in transferring an application from a secondary storage to a primary storage when running the application. (1mk)
  • Help in tracing and removing errors from a program. (1mk)
  • Linkers enable several programs (modules) to subroutines to be connected when running (1mk)

• • Set a printer as a default.
  • The printer may have been configured to the wrong port.
  • Check the picking mechanism of the paper.

    (Award 1 mark for each correct answer)

• • Optical scanners capture data using the principle of light. (1mk)

    Examples – Optical mark recognition. (½mk )

    – Optical bar recognition (½mk )

    – Optical character recognition (½mk)

  • Magnetic scanners capture data by using the principle 2 magnetism.

  Examples – MICR (½mk )

  – Magnetic strip recognition (½mk )

• • Displays al files in drive D whose names begin with P and have extension EXE. (1mk)
  • Format drive A.
• • Command line interface. (1mk)
  • Menu driven interface. (1mk)
  • Graphical use interface (1mk)
• • It is a feature which enables text to automatically flow to the next line if the end of the current one is reached. (1mk)
  • Thesaurus is a feature used to find synomus and autonymus. (1mk)

• Telecommuting is a term used to refer to a situation where an employee works usually at home using a computer connected to the workplace network. (1mk)
• • Source program refers to the program written in its original language (source code) either assembly or high level. (2mks)
  • Object code is the machine code equivalent. It is the program in compute language. (2mks)
• • Transforming of raw data to finished waited information. (2mks)
  • Stages through which data passes before it becomes the finished and wanted information. (2mks)
• • Authenticity
  • Documentation
  • User needs
  • Reliability
  • User friendliness
  • Cost
  • Compatibility and system configurations
  • Portability

(Any correct answer award 1 mark)

1 x 4 = 4mks

SECTION B

• • Program Even numbers (input, output):

    {Program used to generate even numbers between 0 and 201}

    Var

    Begin, ½mk

    Even = 2 1mk

    Repeat 1mk

    Write even 1mk

    Even = Even + 2 1mk

    Until Even = 200 1mk

    End. ½mk

    * Also accept use of other control structures such as While… DO
    

  • )

  ½

1

1

1

1

 ½

• Give types used in structural programming..
• • Real
  • Integer
  • Char
  • String
  • Boalean.

• (a)
  • This is a computer language that uses binary digits to represent data and information. (2mks)
  • Refer to language processors such as assembler, interpreter and compilers that translate the source code to object code. (2mks)

(b)

1. Parallel changeover. (1mk)
2. Direct changeover. (1mk)
3. Phase changeover. (1mk)

(c)

• During investigation and fact finding. (2mk)

Advantages

• Reliable and accurate.
• Intensive investigation.
• Questions can be rephrased for clarification.
• Non.-verbal communication like facial expression can be used and observed.
• Feedback is obtained instantly

Disadvantages

• Expensive and time consuming.
• Interviews are difficult to prepare and organize.
• The interviewee may be reluctant to answer some questions.
• Subjective.

• • A computer program which performs tasks that would otherwise requires skills of human expert if done by people. (2mks)
  • (i) A robot is a computer controlled device usually in form of mechanical and is used to manipulate objects. (2mks)

    (ii)

    • They are accurate
    • They work under hazardous conditions
    • They can perform a wide variety of tasks
    • Are quite efficient
    • Are fast
    • Cannot get tired nor bored.

      (Any correct answer award 1mk) 4mks

  • (i)This is a person who is skilled in designing and developing computer components.
  • (i) This is a person who is skilled in software development and technical operation of computer hardware.
    • These are skilled persons who maintain, upgrade and repair computers to ensure that all the devices are good working condition.
    • This is a person skilled in writing programs in high level language. (1mk)
    • System analyst whose responsibility is to design a new system, team up with programmers to ensure smooth coding and carries out system review and maintenance. (1mk)

• Universities – Nairobi, Kenyatta, JKUAT, Egerton, Moi.
• Polytechnics – Kenya, Mombasa, and Eldoret polytechnic.
• College – Strathmore e.t.c
• Institutes – Kisumu institute, Kabete institute, Kiambu institute, Mombasa institute. (3 mks)

• • Functions are predefined formula that can be used quickly instead of having to create a new one each time a calculation has to be carried out. (1mk)

    – Formulas are user defined mathematical expressions that create relationship between cells and return a value in chosen cells. (1mk)

  • It counts the number of occurrences of the word “oranges” in the range A5: DB.(2mks)

• This is where database are created for different departments in an organizations in different computers that are networked (2mks)

(ii) – Searching of items is fast. (1mk)

– No interference of other departments data (1mk)

• – used to enter data into tables.

  – Display data from tables and queries.

• – Ms word

  – WordStar

  – word perfect etc

  For Any word processor package award

  1 mark (max = 2mks).

• (a)

1. Random- (direct) (½)
2. Serial (½)
3. Serial (½)
4. Direct (½)

(b) 1110₂ – 101₂

Change nuend to 4 digits

101 0101  (1mk)

Find the complement of nuend

0101 1010  (1mk)

Carry over the overflow  (1mk)

• Convert 0.375₁₀ into binary notation.

Solution:

 ½

 ½

 ½ 2mks

 ½

• This is the way in which computer and other devices have been arranged or how data is passed from one computer to another. (2mks)
• • Star topology  (½)
  • Bus topology  (½)
  • Mesh topology (½)
  • Ring topology  (½)