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Q&A-KCSE Computer Studies Paper 1

Differentiate between a compiled and an interpreted program

  • A compiled program will only execute on a processor of specific type/family/with same instruction set
  • A program run using an interpreter can execute on a computer with any type of processor

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

Utility software are operating system programs designed to maintain the functionality of a computer system.

Describe three types of utility software that are provided to help maintain the security and integrity of computer data.

  1. Virus scanning / Anti-virus. Used to locate and delete viruses / scans and compares files with databases of known viruses.
  2. Firewall: checks data packets / examines source address / filters out unexpected packets.
  3. Back up. Copies data onto a separate storage device for use if the original data is lost or corrupted.

(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

Data integrity in a database can be divided into three categories: referential integrity, domain integrity and entity integrity.

(a)Outline the meaning of each of the following.

(i) Referential integrity

(ii) Entity integrity

(b) Describe how data integrity can improve the process of database management. (2 marks)

(i) Referential integrity

  • Two entities that are related require that a foreign key must have a matching primary key

(ii) Entity integrity

  • Entity integrity specifies that the Primary Keys on every instance of an entity must be kept, must be unique and must have values other than NULL

(b) Describe how data integrity can improve the process of database management. (2 marks)

  • Data integrity is the maintenance of, and the assurance of, data accuracy and consistency over its entire life-cycle and is a critical aspect to the design, implementation, and usage of any system that stores, processes, or retrieves data
  • The overall intent of any data integrity technique is the same: ensure data is recorded exactly as intended (such as a database correctly rejecting mutually exclusive possibilities)

Describe one way developers ensure that their software addresses inclusivity issues.

Incorporate language support features in their software, which allows users to select their preferred language. This can be achieved through multi-language user interfaces and providing translation capabilities. By doing so, developers address language barriers and make the software accessible to a broader audience, demonstrating a commitment to cultural inclusivity.

Gender inclusivity – use gender-neutral language in examples

Cultural/Racial inclusivity – use a variety of ethnicities in photos

Ability inclusivity – represent awareness of disability in some examples

Sexual preference inclusivity – use language that is supportive of LGBTQI+ people

Explain the difference between how the IMAP (Internet message access protocol) and SMTP (simple mail transfer protocol) protocols are used

IMAP

  • Retrieves/accesses/downloads (a copy of an) e-mail
  • Allows synchronisation/management of account

SMTP:

  • Sends/forwards/transmits e-mai

State three features of the fifth generation computers (3mks)    [2017 paper 1]

  • Artificial intelligence
  • Parallel processing
  • Natural language processing
  • quantum computing

State four factors to consider when acquiring computer software

  • Authenticity
  • Users' needs
  • Availability of documentation
  • Cost
  • Compatibility
  • Upgradability
  • Portability

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.

 

KCSE 2016 COMPUTER STUDIES PAPER 1

A manager wishes to replace the current manual system with a computerized one. Describe three areas that must be evaluated to justify the replacement  (6 marks)

  • Technical feasibility
  • Does the current technology suffice
  • Economic feasibility
  • Benefits outweigh costs/ whether the project is cost effective
  • Schedule feasibility
  • Can it be done within the schedule

Headache, back and neck pain may result from the use of computers. State how each of them can be minimized (2mks)

  • Proper lighting
  • Regular breaks
  • Use of antiglare
  • Correct position of the screen
  • Ergonomic furniture

Students of a school intended to elect their school Captain by secret ballot.  State three ways in which computers can be used to improve the election process                           (3mks)

  • Registrations of voters
  • Voter identification
  • Actual voting
  • Tallying

Differentiate between Physical and logical topologies

  • Physical topology deals with the placement of nodes
  • Logical topology deals with the data flow  in the network

A company has decided to deliver its products online to international customers. It has employed you as a project manager to determine whether this is a viable business decision. You choose to conduct a feasibility study. Outline the purpose of a feasibility study using two components associated with this process.

  • It covers many aspects that will be used to decide whether to go ahead with the project or not.
  • The main components are technical, operational, economic, legal and scheduling.

State the factors that affect the performance of the CPU

Number of cores
The number of cores a processor has directly affects the performance of the processor. Each core can perform its own fetch-execute cycle independently of others, so different applications can be allocated to different cores. Quad-core (four-core) and even octa-core (eight-core) processors are becoming common

Cache memory
A processor’s cache is a small portion of incredibly fast memory. It has read and write speeds far higher than hard disk drives and even SSDs. The cache is used to store frequently used information and reduces time wasted in fetching the same information from main memory time and time again

Clock speed
A processor’s clock speed relates to the frequency of the pulses generated by the system clock. The higher the frequency, the more cycles of the fetch-execute cycle can be completed in the same period of time.

Word length
A word is a group of bits that is treated as a single unit by a processor. Words can be used for representing both instructions and data. The length of a word is the number of bits that are assigned to it, with higher word lengths allowing for more bits to be transferred and manipulated as a single unit.

Address bus width
The width of a bus relates to the number wires that make up the bus. Increasing the width of the address bus increases the range of addresses that it can specify, hence increasing the computer’s amount of addressable memory. Adding a single wire doubles the number of addressable memory locations

Data bus width
Increasing the width of the data bus increases the volume of data that can be transferred over the bus at any one time. A wider data bus allows the processor to fetch more data from the main memory in one cycle of the fetch-execute cycle, reducing the number of cycles required to fetch large volumes of data.

State and briefly describe three program control structures

Sequence: Sequential execution of a program one line after another

Selection:  Involve the a decision between two or more options e.g  if...then...else

Loops/Repetitions: Used for looping i.e a line of code can be made to execute a given number times before terminating.

State two effects of a computer virus

  • memory used up/slows down computer/alters setting/systems failure
  • erases files/erases data/corrupts data/data needs restoring
  • infects other computers on the network
  • production loss/financial loss

Explain why it is not always true that a computer which has  a quad-core processor runs twice as fast as a computer with a dual-core processor

 

  • Software may be designed to run on 1 core and not multiple cores
  • depends on the task(s)  i.e some tasks cannot be split across cores
  • Clock speed also affects speed i.e dual core may have a faster clock speed and quad-core may have slower clock speed so one task may be run faster/slower
  • RAM size also affects speed i.e Quad-core may have less RAM  amount of VM being used
  • Cache size also affects speed i.e Quad-core may have less cache

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.

802.3 is the standard for ethernet wired networks and 802.11x is the standard for ethernet
wireless networks.
Outline why standards such as these are important in the development of network devices and
software.

  • Standards specify a set of rules for hardware and/or software used in network communications. Because all manufacturers must adhere to the standards when manufacturing network hardware or software, it means that all devices should be able to communicate, regardless of manufacturer.

What is a source code as used in computer programming?

  • It is a program written in a high level langauage