admin@kcseforecast.com

Q&A-KCSE Computer Studies Paper 1

What is entity integrity?

  • It ensures that each row has a unique and non-null primary key
Question Image

For your item named in (a) describe two different tasks that the microprocessor performs.

  • camera film speed, position (end of film), distance, light
  • washing machine amount of water, speed of wash/temperature/time
  • fridge temperature, display panel
  • air conditioning temperature, timing, display pane
Question Image

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
Question Image

Explain, with examples where appropriate, the following five computer terms.

(a) Buffer

(b)batch processing

(c) e-commerce

(d) simulation

(a) Buffer

  • temporary storage or memory which compensates for the difference speed of peripherals and the CPU

(b)batch processing

  • processing doesn’t start until all data is collected
  • JCL (any reference to Job Control Language)
  • no need for user interaction
  • processed all in one go
  • done at “quiet” times
  • e.g. billing, payroll, cheque processing

(c) e-commerce

  • electronic commerce
  • buying and selling products/services using the internet/computer networks

(d) simulation

  • studying the behaviour of a system by using a model/mathematical representation
  • results can be predicted
  • e.g. flight (or other) simulator, modelling hazardous chemical process

(e) Email

  • sending messages from one device to another using computer networks/Internet
Question Image

Outline three ways through which ICT can used in marketing

ICT is used to create e-commerce platforms that have made business transactions easier and convenient by allowing customers make purchases and payments from anywhere at any time

ICT is used by marketing agents to create exciting multimedia presentations concerning products or services and present them to the target customers using presentation software such MS PowerPoint

Using multimedia, presentation and animation software, it is possible to design attractive advert materials and video clips to display on billboards, broadcast over a television or uploaded on the internet


 

Question Image

Sarah uses a range of computing devices to complete her studies, including a desktop computer at home, a laptop at school and her mobile phone. Outline two advantages of cloud computing for Sarah.

Cloud computing refers to the delivery of on-demand computing resources over the internet. Instead of relying on a local server or personal computer, cloud computing allows users to access and utilize a wide range of computing services and resources hosted on remote servers.

  • Sarah could keep all of her files in the cloud and easily access these with her devices. This way she does not have to keep different version on her desktop and laptop.
  • Flexibility she could access the files from other devices such as the library etc.
  • Disaster recovery if she accidently dropped or damaged a device – all files would be easy to access.
Question Image

A company has decided to use a computer for stock control. Describe the process of systems development from the time the decision was made to proceed with computerisation until final testing.

specify output requirements
design documents/screen displays
data for input/storage
form design
storage devices
file structures/access/design
data security/back up files
systems flowchart etc.
implementation i.e. pilot/intermediate/parallel running
testing strategy
training
hardware/software
programming/algorithms
validation
user manual
technical documentation
entering data into system

Question Image

Describe each of the following types of a program errors, giving an example in each case.

(i) Syntax error.
(ii) Logic error.
(iii) Arithmetic error/runtime error

(i) Incorrect use of language, e.g. PLINT instead of PRINT
(ii) A mistake in the structure of the solution, e.g. a jump goes to the wrong line
(iii) Inappropriate arithmetic is used, e.g. division by 0 is attempted

Question Image

Describe the role of the registers and system clock within the fetch-execute cycle.

  • Registers are small amounts of memory available that hold data fetched from memory or data waiting to be stored in memory. A temporary holding place for the instruction that has been fetched.
  • The system clock purpose is to determine the pace of the cycle, each tick of the clock a part of the fetch-execute cycle occurs. Regulates the timing and speed of a computers systems functions.
Question Image

Describe each of the following storage devices

DVD - optical media which use one spiral track; red lasers are used to read and write data on the media surface; makes use of dual-layering technology to increase the storage capacity

ROM - non-volatile memory chip; contents of the chip cannot be altered; it is often used to store the start-up routines in a computer (e.g. the BIOS)

SSD/ Solid State Drive/memory (SSD)

non-volatile memory device that uses NAND flash memories (which consist of millions of transistors wired in series on single circuit boards)

Blue Ray -  optical media that uses blue laser technology to read and write data on the media surface; it uses a single 1.1 mm polycarbonate disc

Question Image

State the differences between a hub and a switch

 

  • switches can send and receive data simultaneously - they are full duplex
  • a hub is half duplex- only one host can communicate at a time.
  • a hub broadcast signals to all computers connected in a network while a switch directs data to its intended destination
Question Image

Explain one drawback to a user if the program is distributed as freeware

The user is not allowed to access the source code so, they cannot tailor the software to their needs and  they cannot fix any bugs in it

The software is still covered by copyright

The user must get the owner’s permission to do anything beyond using it

Question Image

Computer programs require translation to execute. (a) Compilers and interpreters translate high-level programming languages into machine code. Describe the main differences between a compiler and an interpreter.

  • A compiler translates the whole program in one go whereas An interpreter translates each line of code (often an intermediate code) at run time
  • A compiler produces an executable file that will run on the target hardware machine without the compiler being installed  A run time interpreter will be required at run time
  • Compilers tend to be large complex programs Interpreters are smaller simpler programs
  • Interpreted programs can be amended and run without translating whole program Compiled programs have to be re-compiled after a change
  • Compilers compile programs that will usually only run on the target platform (hardware/operating system)  Interpreters will interpret same program (or intermediate code) on different (some virtual) platforms
Question Image

A web server has an internet protocol (IP) address. Give three characteristics of an IP address.

  • consists of values between 0–255 / 0–FFF
  • values are separated by full stops/colons
  • it is a unique address
  • can be static or dynamic
  • can be public or private
  • can be IPv4 / have four groups of digits
  • can be IPv6 / have eight groups of digits
  • in IPv6 :: can replace groups of zeros.
Question Image

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.
Question Image

State three documents that are used during mail merging in word processing

  • Main document
  • Data source
  • merged document
Question Image

What is a computer keyboard?

A computer keyboard is an input device used to enter text, characters, and various commands into a computer or other digital devices.

Question Image

State the functions of the following features in word processors

  • Thesaurus - Is a feature in a word processor that suggest words with the similar or opposite meaning to the one selected
  • Comments: a feature in a word processor that allows a user to attach a remark about the selection
Question Image

Joe plays online games using the world wide web. A sequence of processes is required to open a web page. Describe this sequence of processes

  • URL is clicked/typed into a web browser address bar. The page is requested (by the web browser) so HTML and files are fetched from a web server and the browser collates the page, which is then displayed on the monitor.
  • OR
    URL is clicked/typed into a web browser address bar (1). The browser locates the IP address either in cache or using a DNS server and the browser sends a request to the web server with that IP address web server uses HTTP to send back the requested web page and the browser displays the content of the page .
Question Image

Explain what is meant by a LIFO data structure.

  • Data enters at one end (of a stack)
  • Leaves at the same end
  • Hence 'last in, first out'
Question Image