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Q&A-KCSE Computer Studies Paper 1

Describe the difference between distributed and sequential processing on how they process instructions

  • Sequential processing occurs in the order that the tasks are received while distributed processing where more than one computer or CPU is used to run specific programs.
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Describe the function of a web browser

Convert the HTML into a webpage which is rendered on the screen

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Computer Studies KCSE 2006 Paper 1

SECTION A (40 MARKS)

1.What is meant by

    a)Analogue data

     b)Digital data                           (4 mks)

2. Distinguish between transcription and transposition types of errors and give an example of each  (4mks)

3. a)What are peripheral devices?  (1mk)

   b)Give two examples of peripheral devices  (1mk)

4a)What meant by the term user-friendly as used in software development? (1mk)

  b)Distinguish between the terms single-tasking and multi-user as used in operating systems  (2mks)

5.What actions should be taken in case of a fire outbreak in the computer laboratory?  (4mks)

6a) What is an Internet Service Provider?    (1mk)

  b) An employee in a business company is charged with the responsibility of putting the company advertisements on the Internet.

 i) State the professional title of the employee. (1mk)

ii) Give an example of software used by this employee to carry out the above task.    (1mk)

7.Differentiate between COM ports and LPT ports     (2mks)

8.Explain two ways in which ICT can enhance commerce.  (2mks)

9. Explain the following software terms:

    a) Portability       (1 mk)

    b) Modularity      (1 mk)

10. a) State two application areas of desktop publishing software. (2mks)

     b) Explain the following graphic terms:                                                                                     

     i) Rotate (1 mk)

    ii) Crop  (1mk)

12. a)List two arithmetic operations that can be performed on a row of numeric data in a word processing table.    (1 mk)

     b) In each case of (a) above, write the expression used.  (2mks)

13. List two methods of gathering information during the system development process   (2mks)

14.Name three types of optical disks.(3mks)

15.The diagram below shows a formatted plate surface of a storage disk.

 

 

 

            Shade and label:

            a)         one sector                                                                                ( 1mk)

            b)         One block                                                                                (1mk)

SECTION B (60 MKS)

Answer question 16 and any other three questions from this section in the  space provided

16 a) List two examples of:

       i) Third generation languages    (2mks)

       ii) Object oriented languages    (2 mks)

b) Draw a flowchart to compare three non-equal numeric values A, B, C and prints the largest of the three. (11 mks)

17 a) One of the functions of an operating system is job scheduling.  Explain what is meant by job scheduling.   (1mk)

    b)List and explain three types of user interfaces.                      (6 mks)

    c)Describe the following categories of software:

       i) Firmware                 (1mk)

       ii) Proprietary software  (1mk)

     d) a new company XYZ intends to go into the business of desktop publishing. Advise the company on three computer hardware system specification features to consider as a measure of enhancing performance. (6 mks)

18. a) distinguish between the following sets of terms as used in spreadsheets.        (2mks)

     i)Worksheet and workbook

     ii) Filtering and sorting

     b) State one way in which a user may reverse the last action taken in a spreadsheet package.        (1 mk)

     c)The following is a sample of a payroll. The worksheet row and column headings are marked  1, 2, 3, .  and A, B, C.  respectively

 

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Differentiate between object code and source code

  • Object code refers to a program in machine language while source code to a program in a high level language that must be translated to object code for it to be machine readable
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b) Give one benefit of each type of data transmission

Serial

  • -more accurate/fewer errors over a longer distance
  • -less expensive wiring  
  • less chance of data being skewed/out of synchronization/order
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Describe one effect of not having primary keys in tables in a relational database

Without a primary key, a table in a database may have duplicate rows, making data not uniquely identifiable. This can lead to issues with data integrity and challenges in maintaining relationships between tables. Retrieving and updating specific records becomes problematic, and setting referential integrity constraints is impossible, potentially leading to loss of data.

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Distinguish between a file and a folder

A file is a collection of related data given a unique name while a folder is named storage location on a storage media that contains related files

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A typical computer’s main memory consists of both volatile and non-volatile memory.

a)  i)  Explain what is meant by the term volatile memory                                                            (1mark)

  • Memory content is lost when the power is turned off

ii) What is normally stored in the non-volatile part of a computer’s main memory                       (1mark)

  • The Computer’s BIOS

b) Explain why having cache memory can improve the performance of the CPU                         (2mks)

  • Frequently used data/instructions are store in the cache; Meaning they don’t have to be fetched from the main memory;
  • Data/instructions stored in the cache memory can be accessed faster (than data/instructions stored in the main memory) MAX 2
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Computer Studies Paper 1 2021  KCSE Prediction Section B Qs. 17,18 and 19

17. a) i) Explain the term search as used in the Internet.                                            [2]

A web based application that locates items or information from the World Wide Web

ii) Peter intends to download a movie from the Internet. State the three factors that may determine the total time taken to complete the download.                                           [3]

  • 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

b) Wakulima online is an organization that runs a web based system for assisting farmers to obtain market for their produce. State four technological reasons that may cause a farmer not to access the organization’s system.                                                                                  [4]

  • Poor network/lack of connection
  • Software failure in the system
  • Hardware failure
  • Lack of access rights
  • System overload/hanging
  • Lack of skills/disability/illiteracy
  • Lack of power supply

c) Explain a situation when each of the following Desktop Publishing program features may be used when creating a publication:

i. Cropping                                                                                                               [2]

Applies to graphics – used to trim/remove/hide some portions in the graphics

ii. Transparency                                                                                                         [2]

Used to make background of a graphic to be clear/visible

d. List two areas where infrared waves are used in data communication.                             [2]

18. a) List four activities of the planning stage of systems development.                             Ignore this question, marks redistributed elsewhere

b) Explain a circumstance when each of the following feasibility studies are carried out during systems development.

i. Technical                                                                                                               [3]

Done to determine whether technology exists to support the proposed solution

 

ii. Economic                                                                                                              [3]

Done to determine whether the proposed solution is economically viable

 

iii. Schedule                                                                                                               [3]

Done to determine whether the proposed system can be done within an acceptable time.

c) Table 1 and Table 2 are related tables in a database. Use them to answer the questions that follow.

Table 1

Dept Code

Dept Name

001

Computer

002

Aviation

003

Engineering

 

Table 2

DeptID

Student Registration No.

Student’s Name

002

St01

Alex Too

003

St02

Naomi Komi

002

St03

Peter Kengo

 

i. Identify the appropriate primary key for each table.                    [2]

Table 1 – Dept code, Student Registration No

ii. Explain two benefits of enforcing referential integrity in the database. [4]

  • No record can be added in Table 2 if its corresponding record in Table 1 does not exist
  • No record in Table 1 can be deleted without first deleting the corresponding record in Table 2
  • Reduces data redundancies/ensures integrity
  • Prevents deletion of related table

19. a) Describe each of the following validation checks as used in data processing.

i. Preserve check                                                                                                      [2]

Ignore this question, marks redistributed elsewhere

ii. Data type check                                                                                                    [2]

Ensure correct type of data is entered for the field

iii. Check digit                                                                                                           [2]

This is a number added/calculated by the computer to a binary number. The check digit ensures correct transmission of the binary number.

b. Write each of the following abbreviations in full:

i) BCD                                                                                                                                    [1½]

Binary Coded Decimal

ii) EBCD                                                                                                                                 [

This question was thrown out and marks redistributed elsewhere

iii) ASCII                                                                                                                    [1½]

American Standard Code for Information Interchange

c) Using 10-bits binary number system, perform the following decimal operation using two’s complement.                                                                                                                                   [6]

12910 - 12810

+129 = 00 1000 0001

128 = 00 1000 0000

-128 = 11 0111 1111 (ones complement)

                            +1

          11 1000 0000 (Twos complement)

129- 128

     00 1000 0001

+ 11 1000 0000

 100 0000 0001

Hence = 00 0000 00012 or 12 (the overflow bit is ignored)

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Give a reason why HMTL is not regarded as a programming language

  •  It does not have declaration part
  • It does not  have control structures
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Aeroplanes now use Global Positioning Systems (GPS) to determine their location.

Describe how the computer on board the aeroplane uses GPS to find its exact location

Give two benefits of using GPS in this application

Describe how the computer on board the aeroplane uses GPS to find its exact location

satellites transmit signals to onboard computers
computers receive/interpret these signals
system depends on very accurate timing/use of atomic clocks
each satellite transmits data indicating location and time
computer in aeroplane calculates location based on at least three satellites
at least 24 satellites in operation at any one time
position accurate to within one metre
can also calculate altitude of aeroplane
ref to “triangulation”:

Give two benefits of using GPS in this application

safer as the known location is exact/more accurate
reduces the possibility of pilot error
allows accurate estimation of arrival time
display and guide the pilot to the nearest airport in case of emergency

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What is a computer system ?

A computer system refers to computer components that collectively function as a single unit to achieve the desired goal. It can also be defined as a collection of hardware, software, and liveware that work together to receive, process, and manage data

Social engineering is where someone is tricked or manipulated into providing secure information or access to a secure system. Describe each of the following social engineering techniques.

Blagging

  • This is where a victim is tricked/persuaded by a fraudster to give their details or payment information for a false reason/purpose;

Phishing

  • This is where the victim receives and responds to communication that appears to be from a valid or known source but is in fact fraudulent. (It allows the fraudster to capture private information before the victim realises);

Shouldering

  • This is where someone watches and records\remembers a victim entering their pin or security information such as passwords. (They can then use this information to gain access to a system)
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Joelle’s parent also uses the firewall to limit the websites that Joelle can access.
Explain how the firewall is used to limit the websites that Joelle can access

(The parent can) set criteria for the websites she is allowed to visit such as a whitelist/blacklist of websites. The firewall will examine the data/traffic incoming and outgoing from her computer. If data is sent from a website that is not allowed, it will be blocked

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Explain two computer hardware features that may be considered when selecting a laptop computer to be used in developing a KCSE computer studies project (4mks)

Multimedia Capability - A laptop with strong multimedia capabilities is essential for a computer studies project submitted on CD-RW. This ensures that the laptop can efficiently handle multimedia content, providing a seamless experience in creating and presenting project materials.

Processor Speed - Opting for a laptop with a high processor speed is crucial. This feature enables the smooth execution of multiple applications simultaneously, enhancing overall project efficiency and reducing processing delays.

Hard Disk Capacity - Consider a laptop with ample hard disk capacity, as the Microsoft Office suite used in computer projects requires significant space for the installation and storage of project files. A spacious hard drive ensures that there is sufficient room for data and applications.

Main Memory Capacity - Given that students often work with multiple programs concurrently during a project, it's important to choose a laptop with an adequate main memory size. A smaller main memory may result in performance issues, hindering the seamless operation of various software applications during project development.

 

Describe what is meant by ‘RAID 10’.

  • RAID 10 is a combination of RAID 0 (zero) and RAID 1 (one)
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A workshop has a lot of heavy machinery operating throughout the day and requires a cable to connect a workstation to a switch. Which of the following, unshielded twisted pair (UTP) or shielded twisted pair (STP) cable, would be the more suitable? Justify your response.

Shielded twisted pair cable:
A twisted pair cable is made up of four pairs of twisted copper wires, a shielded twisted pair cable applies a shield to each one of the pairs on a cable or to all of the pairs together. This shield can reduce EMI (electromagnetic interference), which would be emitted from heavy machinery. This increased data transmission quality in the workshop. STP can also reduce crosstalk.

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Differentiate between a switch and a hub
A switch forwards data packets directly to the address of the node using point to point transmission method. A hub broadcast the data packets to all computers on the network
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A computer operates as a binary digital device. Explain why binary is used to represent computer data.

  • Binary can represent two states because computer circuits use transistors, which can either be on or off
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State any four applications of electronic spreadsheets

  • Financial accounting
  • Prediction and forecasting
  • Inventory keeping
  • Budgeting
  • Keeping records
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