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Q&A-KCSE Computer Studies Paper 1

Identify four different types of computer network.

  1. MAN
  2. WAN
  3. PAN
  4. LAN
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State three features of a typical operating system

- (provides) user interface
input/output control
security
handling interrupts
spooling
memory management
processor management
utilities (e.g. copy, save, delete, re-name, etc.)
maintain user accounts
load/run software
error reporting/handling
multiprogramming
batch processing (JCL)/real time processing
multitasking/multiuser/multi-access
file management

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Name three of the stages in the system life cycle

fact finding
feasibility study
analysis
design
testing
documentation
implementation/changeover/installation
evaluation
maintenance

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The following are software classified according to the end user licence agreement. Briefly describe each of them:

open source software, freeware, shareware, and proprietary software

Open source : refers to software provided freely with its source code. The user can modify and redistribute the software.

Freeware: these are software that can be downloaded for free and distributed, buta  the source code is hidden and cannot be altered.

Shareware: is software that is available for free within a given trial period, after which it must be bought.

Proprietary: software made for commercial purposes. The source code is hidden, and it can only be used after paying for a licence.

 

Ahmed uses the Internet for some time and is puzzled by the terminology.
(a) Draw a line to match each description to the appropriate technical term.

  • a computer that responds to requests to provide information and services over the Internet - an Internet server
  • defines how messages are transmitted and formatted over the Internet-HTTP
  • software that enables users to access/view documents and other resources on the Internet - Browser     
  • numerical ID for each device on the Internet-IP address
  • unique ID for a network interface card  -MAC address
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State a stage in system development where each of the following activities are carried out    (KCSE 2018)

(a) Identifying technologies that may be used in a proposed system

  • System Analysis/Information gathering/Problem recognition

(b) Identifying the shortcomings of the old system

  • Problem definition

(c) Prepares the software migration plan

  • Implementation stage
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State advantages and disadvantages of the following system implementation strategies

Phased:
Advantages:

  • only a small part of the operation affected if new system fails
  •  no need to pay for two sets of wages

Disadvantages:

  •  time consuming (each part needs testing fully before expanding system)

Pilot:
Advantages:

  • if new system fails, only that part will be affected
  • possible to gradually train staff on pilot before whole system changes over

Disadvantages:

  •  time consuming (waiting to see how pilot works before rolling out to rest of the organisation)

Direct:
Advantages:

  •  less likely to malfunction since fully tested
  • immediate benefits/less time wasted
  •  reduced costs (only one system so no need to duplicate staff)

Disadvantages:

  • disastrous if the new systems does fail

Parallel:
Advantages:

  •  if new system goes down, there is a backup system in place
  • possible to gradually train staff/staff have time to get used to the new system

 

 

 

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State what is meant by each of the following modes of data  processing

(i) Batch processing.
(ii) Real-time processing.
(iii) Online processing.
(iv) Off-line processing.

(i) Jobs collected together for processing at a later time
(ii) Output produced quickly enough to affect the next input
(iii) User has direct contact with the processor
(iv) User cannot communicate directly with the processor

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State advantages and disadvantages of Solid State Drives and Hard Disk Drives

Advantages of  of Hard Disk Drive

  • Hard disk drives are cheaper per gigabyte than solid state drives.
  • Hard disks have a longer lifespan than solid state drives

Disadvantages of Hard Disk Drives

  • Consumes more power than SDD
  • They are noisy.
  • They are slower than solid state drives.
  • They are susceptible to wear and tear as they have movable parts.

Advantages of Solid State Drives

  • Are faster than HDDs
  • It is more durable as it does not have moving parts
  • Consumes less power
  • Are not noisy

Disadvantages of SDD

  • It costs more than a conventional hard disk
  • Have fewer write/erase cycles compared to a hard disk drive
  • Lost data cannot not be recovered
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Describe how the database can be recovered from a system failure

  • mirrored hard disk/hot standby/second computer
  • re-run the old master file with the transaction file
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(iv) Identify the part of the CPU that sends signals to the other components.

 

 Control unit

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Describe two benefits of using USB connections between a computer and a device.

  • devices are automatically detected and configured when initially attached
  • Impossible to connect device incorrectly/connector only fits one way
  • has become the industry standard
  • supports multiple data transmission speeds
  • lots of support base for USB software developers
  • supported by many operating systems
  • backward compatible
  • faster transmission compared to wireless
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Distinguish between Incremental and Full backup


Incremental:

  • Only the changes need to be backed up
  • The software/OS/settings are unlikely to have changed between backups
  • Small number of files likely to be used/edited between backups
  • Take less time to backup
  • Each backup will take less memory space to store

Full:

  • Backup all the data/files and software
  • It might not take a significant time to back up entire system
  • He might only have a small number of files to be backed up each time
  • Safer as have more past versions to revert to
  • User may have changed settings on computer
  • Faster to restore the backup
  • Needs to do a full before he can do an incremental
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What situations are likely to call for the use of Direct Changed Over?

  • where the new system is completely different from the old one
  • if there has been extensive testing of the system and the system analyst has confidence in its functionality
  • If the system is not critical
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Explain how the techniques of

(i) verification,
(ii) validation
are used to ensure that the stored data is as accurate as possible.

Dual input of data

  • Two inputs are compared by the system and any discrepancies are reported (and not stored.)
  • Data input once, either printed out or checked on the screen and  errors corrected

 Rules are given to the processor

  • Only accept A, B, C, D, E, F, G i.e Any other input rejected.

Drop-down list/radio buttons

  • Provides only valid inputs, so no other validation is required
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KCSE 2016 COMPUTER STUDIES PAPER 1

State the function of each of the following keys on the computer keyboard :  (2mks)

Backspace;

  • Deletes characters to the left of the cursor

Insert

  • Add characters at the cursor position
  • Toggles between overtype and insert modes

An organization intends to replace an existing system by carrying out the process in stages .

Name the implementation strategy ;  (1mk)

  • Phased change-over

Give two reasons why the  organization is opting to use the implementation strategy  in (a) above (2mks)

  • Gives employees time to learn
  • Organizations can revert to the old system in case of failure
  • Reduces resistance by the employee
  • It is easier to find system errors as you are dealing with only one part at a time
  • Accessing parts of the old system is still is possible in case of failure of the new system
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List four input devices used to capture data by way of scanning                 

Optical Mark Recognition; Optical Character Recognition; Magnetic Ink Character Recognition ; Optical Bar Recognition

Giving answers as readers is also acceptable, that is, Optical Character Readers, Magnetic Ink Character Readers; Optical Mark Readers

 

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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Briefly describe the following

Multitasking - the  capability of an operating system to enable users to run two or more programs at once on a single computer

Real time processing - data processing system in which the time interval required to process and respond to inputs is so small that the response itself is useful for controlling the physical activity of a process

Time-sharing processing  - a processing mode in which the central processor serves two or more users with different processing requirements (tasks)

On-line processing - is that type of processing where the result of data processing transaction is available immediately

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What is meant by RAID technology?

RAID (Redundant Array of Independent Disks) technology refers to a method of combining multiple physical disk drives into a logical unit to improve performance, data availability, and data redundancy. RAID technology is commonly used in storage systems to provide fault tolerance, data protection, and increased storage performance.

The primary purpose of RAID is to create a more reliable and robust storage solution by spreading data across multiple drives and implementing various data redundancy techniques. This helps to mitigate the risk of data loss and system downtime in case of drive failures.

There are different levels or configurations of RAID, each offering different features and trade-offs. The most commonly used RAID levels are:

  1. RAID 0 (Striping): Data is split evenly across multiple drives, resulting in increased performance as data can be accessed from multiple drives simultaneously. However, there is no redundancy, so if one drive fails, data loss can occur.

  2. RAID 1 (Mirroring): Data is duplicated or mirrored across two drives, providing redundancy. If one drive fails, the other drive can still function and serve the data. RAID 1 offers data protection but does not offer increased performance.

  3. RAID 5 (Striping with Parity): Data and parity information are striped across multiple drives, providing both increased performance and fault tolerance. Parity information allows for the recovery of data in case of a single drive failure. RAID 5 requires a minimum of three drives.

  4. RAID 10 (Combination of Mirroring and Striping): RAID 10 combines elements of RAID 1 and RAID 0. It involves mirroring data across two sets of drives and then striping the mirrored sets for increased performance and fault tolerance. RAID 10 provides high levels of data redundancy and performance but requires a minimum of four drives.

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