1 - Theory of Computer Science / Input Devices (Manual)

Exam Questions - Input Devices (Manual)

Example Question 1

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4

(a) Question 4 (a) asks you to give two disadvantages of restaurant staff using a keyboard to enter order details. For this question you need to think of the practicality issues that may occur in this situation.

​Answers
  • Easy to make a mistake
  • Can be slow if not trained
  • Dirt / Food can get into keys

(b) Part (b) of the question wants you to explain why it would be better for the restaurant to use a concept keyboard. It includes a description of what a concept keyboard is and how it would be used.

Key point - The question asks you to explain the benefits.  Simply naming two benefits will not get you two marks! you need to explain both of them.
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Answers
  • Fewer typing errors would be made...
  • ...Because one button is pressed to order an item
  • Speed up the time to enter an order...
  • ...Because fewer buttons are pressed to complete the order
  • May require less training...
  • ...Because it is easier to identify an order item from its image rather than typing it
  • Can stop dirt/food damage...
  • ...Normally has a protective layer // Because there are no keys 

Example Question 2

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(c)

​Question (c) requires you to give an explanation of how an infrared touch screen works. The question is worth 4 marks so at least 4 points should be given.

Each of the following points would be worth 1 mark each (Max 4)

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  • (Infrared) rays are sent across screen (from edges)
  • Has sensors around edge // sensors capture beams
  • (Infrared) rays form a grid across the screen
  • (Infrared) ray is broken (by a finger blocking a beam)
  • Calculation is made (on where beam is broken) to locate the touch

Example Question 3

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10

(a) Question 10 (a) asks for an explanation of how capacitive touch screens work.  Any four of the following points would gain 1 mark:

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  • Conductive layer
  • An electrostatic / electric field is created
  • Sensors around the screen monitor the electrostatic field
  • Then touched (electrostatic) charge is transferred to finger
  • Location of touch is calculated

(b)  Question 10 (b) asks you why the capacitive touch screen will not work if the person is wearing gloves. This question is worth 2 marks so two points should be given.

Answers
  • Gloves are not conductive // gloves are an insulator
  • Block current / charge from finger
  • Stop the electrostatic field being disturbed / changes

(c) The final part of this question asks you how the mobile phone could be used without having to remove the gloves. 

This question asks you to explain, this means that 1 mark is given for naming a method and one mark is given for explaining how it works.

Answers
  • Use a conductive stylus...
  • ...This will allow the charge to be disturbed / charged
  • Use capacitive gloves...
  • ...This will allow the charge to be disturbed / charged
  • Use a natural language interface / voice operated interface...
  • ...Could give vocal commands to this device

Example Question 4

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2

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