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Question 17N.3.sl.TZ0.a

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Date November 2017 Marks available [Maximum mark: 2] Reference code 17N.3.sl.TZ0.a
Level sl Paper 3 Time zone TZ0
Command term Outline Question number a Adapted from N/A
a.
[Maximum mark: 2]
17N.3.sl.TZ0.a

The development of materials with unique properties is critical to advances in industry.

Outline two properties a substance should have to be used as liquid-crystal in a liquid-crystal display.

[2]

Markscheme

Any two of:

ability to form a LC phase

chemically stable

«LC phase that is» stable over suitable temperature range 

polar

OR

being able to change orientation with applied electric field

rapid switching speed «responds to changes of voltage quickly»

Accept “ability of molecules to transmit light under certain conditions” OR “rodshaped molecules” OR “stable to light/not light sensitive”.

[Max 2 Marks]

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