UPSC Prelims 2017 GS Paper I · Q74 of 100 General Science medium

Organic Light Emitting Diodes (OLEDs) are used to create digital display in many devices. What are the advantages of OLED displays over Liquid Crystal displays ? 1. OLED displays can be fabricated on flexible plastic substrates. 2. Roll-up displays embedded in clothing can be made using OLEDs. 3. Transparent displays are possible using OLEDs. Select the correct answer using the code given below :

  1. (a) 1 and 3 only
  2. (b) 2 only
  3. (c) 1, 2 and 3 ✓ UPSC's answer
  4. (d) None of the above statements is correct

Why the answer is (c)

• OLEDs emit light from thin organic layers themselves, needing no backlight, unlike LCDs.

• This lets them be printed on flexible plastic substrates (1), made into roll-up or wearable displays woven into clothing (2), and built as transparent displays (3) since the organic layers can be nearly clear when off.

• They also give deeper blacks, wider viewing angles and lower power for dark content.

• Hence 1, 2 and 3, option (c).

Why the other options are wrong

(a) 1 and 3 only
Roll-up wearable displays are also possible with OLEDs.
(b) 2 only
Flexible and transparent displays are also OLED advantages.
(d) None of the above statements is correct
All three are genuine OLED advantages.

Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2017, held on 18 June 2017. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

Reading the answer is not the same as getting it right under a clock. Practise this question with UPSC's negative marking, and anything you miss goes into an error notebook until you get it right twice.

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