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Q&A- Computer Studies

Q1. state two places where robots are used.

  • car factories/factories
  • chemical/nuclear factories
  • production lines
  • warehouses
  • deep in the ocean/down mines
  • on other planets/in space
  • road junctions

Q2. state two benefits of using robots

  • reduced labour costs/do not need paying
  • reduced cost of goods
  • improve speed of production/productivity
  • high degree of accuracy/precision/less errors
  • can operate where humans can not go
  • do not take breaks/holidays/get tired
  • work 24 hrs a day
  • reduce accidents at traffic lights
  • improve traffic flow
  • can work in dangerous conditions

Q3. a supermarket uses point of sale (pos) terminals at the checkout for scanning barcodes on the products. (a) state two items of data that are stored on the barcode. (b) describe how the computer system checks that the barcode has been read correctly. (c) state the type of file access that is used to get the price from the central computer. (d) explain how the system updates the file when an item has been sold.

(a) State two items of data that are stored on the barcode.

  • check digit
  • product number/item number/code
  • country of origin
  • manufacturers number/code
  • weight
  • price

(b) Describe how the computer system checks that the barcode has been read correctly.

  • check digit calculation is performed on the check digit, remainder = 0 if the barcode has been read correctly
  • weights and modulus 11 and use remainder
  • or subtractions and addition and use answer


(c) State the type of file access that is used to get the price from the central computer.

  • random/direct/online

(d) Explain how the system updates the file when an item has been sold.

  • search file/master file using barcode number/product code and decrease number in stock/increase quantity sold

Q4. give two benefits for the supermarket manager of using point of sale (pos) terminals.

  • more accurate/improved stock control/recording system/automatic
  • reordering/automatic updating of stock file
  • less staff/wages needed
  • sales statistics now available
  • faster throughput
  • itemised receipt
  • records every transaction
  • records staff work rates
  • less pilfering by staff/easier to identify pilfering
  • less errors
  • faster calculations
  • links to EFTPOS

Q5. state two benefits of using computerised traffic control systems.

  • Better/improved traffic flow control
  • reduces accidents
  • keeps delays to a minimum
  • reduces pollution
  • cars use less fuel

Q6. state two benefits of using computerised traffic control systems

  • Detecting congestion.
  • Synchronizing activity between traffic lights.
  • Updating traffic light timing in real time.
  • Updating and informing drivers of ideal speeds.
  •  Prioritizing transportation flow.
  •  Reduce congestion and time spent on the road
  • By reducing congestion it will decrease pollution
  • Prioritize traffic based on changes in traffic conditions in real time.
  • This system is also helpful to reduce infrastructure damage. It is possible to identify overloaded vehicles and provide them with appropriate ways or roads, which will reduce road damage.

Q7. describe the input, processing and output from a computerised traffic-control system.

input

  • from sensors
  • from camera images [Max 2]

processing

  • analyse data from sensors
  • calculate average traffic flow/speed
  • send signals to adjust change lights/timing

output

  • change lights at the junction
  • change timing plan

Q8. describe what the traffic control program should do when an emergency occurs.

give uninterrupted path through the system of linked traffic lights/
green link - wave
turn all lights to red
activate emergency generator
alarm

Q9. name two other input/output devices used at the pos terminal apart from keyboard and barcode reader and give a use for each device.

device: beeper/loud speaker
use: to indicate barcode correctly read/error in reading barcode
device: (LCD) screen/monitor
use: to show prices and other information about goods
device: touch screen
use: to show prices and other information about goods/to select items that need to be
weighed/identified
device: weighing machine
use: to find weight of loose items (e.g. fruit) to enable pricing
device: (magnetic) card reader/CHIP and PIN reader
use: to read customer’s debit/credit card/enable customer to pay for goods using a
credit or debit card
device: printer
use: to print receipts

Q10. describe two features you would expect to see in the expert system’s interactive user interface.

– multiple choice/yes-no answers
– easy to understand interface e.g. use of icons/drop down menus etc.
– output shown as % probabilities of fault

Q11. apart from the user interface, name three other components that make up a typical expert system.

– knowledge base
– rule(s) base
– inference engine
– explanation system
– (expert system) shel

Q12. state what is meant by computer aided design (cad). give three different applications that make use of cad. name three specialist input/output devices used in cad.

software that can be used to design new products/amend existing products
makes use of features such as 2D, 3D, wire frames, library of parts, links to CAM

Give three different applications that make use of CAD.

aerospace
architecture
designing cars
designing consumer goods
chemical/nuclear plant design
designing electronic circuit boards
ergonomic design
landscape/garden design

Name three specialist input/output devices used in CAD.

large monitor/screen with hi-res
touch screen
plotter
space mouse/space ball/4D device
3D glasses (in some applications)
light pen
graphics tablet
3D printer
3D scanner

Q13. (a) name two pieces of hardware needed to enable video-conferencing to take place using a standard computer system. (b) state one piece of specialist software needed to carry out video-conferencing.

(a)

webcam
speakers
microphone
broadband modem

(b)

use of CODEC (converts/compresses analogue data into digital data)
echo cancellation s/ware (allows talking in real time/keeps everything in sync)
compression s/ware for video/audio
s/ware to access broadband/networking

Q14. state advantages and disadvantages of video conferencing

Advantages

immediate response to questions/queries
can see each other watch body language etc.
easier to have several participants (would be difficult using instant messaging if
several people involved)

Disadvantages

need for expensive equipment/high set up costs
sometimes synchronisation problems make it difficult for delegates
need to train people to use the new technology
greater use of bandwidth

Q15. give one reason why use of video-conferencing has increased over the last ten years.

faster communications now widely available
safety reasons, e.g. increase in terrorist attacks on international flights
reduced transportation/accommodation/hardware costs
environmental issues, e.g. reduced carbon footprint
increase in multinational working