O-LevelComputer ScienceHardware2210/12 · May/June 2018 · Q108 Marks

Alexandra has a new mobile device. It has a touch screen that uses capacitive technology.

(a)Describe how a capacitive touch screen registers Alexandra's touch.[4]
(b)(i)Alexandra is wearing gloves because it is cold. She presses an icon on her touch screen but her action is not registered. Explain why the touch screen will not register her touch.[2]
(b)(ii)Alexandra does not want to remove her gloves. Explain how Alexandra could use her mobile device whilst still wearing gloves.[2]

Mark scheme

Marking points from the official mark scheme (May/June 2018). The mark or mark type is shown in brackets.

[1] (a) Conductive layer
[1] (a) An electrostatic/electric field is created
[1] (a) Sensor(s) (around the screen) monitor the electrostatic field
[1] (a) When touched (electrostatic) charge is transferred to finger
[1] (a) Location of touch is calculated // Co-ordinates used to calculate touch
[1] (b)(i) Gloves are not conductive // Gloves are an insulator
[1] (b)(i) Block current/charge from finger / body / person
[1] (b)(i) Stop the electrostatic field being disturbed/changed
[1] (b)(ii) She could use a (conductive) stylus...
[1] (b)(ii) ... this will allow the charge to be charged/disturbed
[1] (b)(ii) She could use capacitive gloves...
[1] (b)(ii) ... this will allow the charge to be charged/disturbed
[1] (b)(ii) She could use a natural language interface/voice operated interface ...
[1] (b)(ii) ... she could give vocal commands to the device

On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.