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2 questions · 2012 · answers as per the UPSC key

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UPSC 2012 · Q14 · Science & Technology › Materials & Engineering · Save

Graphene is frequently in news recently. What is its importance?

  1. It is a two-dimensional material and has good electrical conductivity.
  2. It is one of the thinnest but strongest materials tested so far.
  3. It is entirely made of silicon and has high optical transparency.
  4. It can be used as 'conducting electrodes' required for touch screens, LCDs and organic LEDs.

Which of the statements given above are correct?

(a) 1 and 2 only
(b) 3 and 4 only
(c) 1, 2 and 4 only
(d) 1, 2, 3 and 4
Show answer
Answer: (c) 1, 2 and 4 only
UPSC 2012 · Q86 · Science & Technology › Materials & Engineering · Save

Recently, there has been a concern over the short supply of a group of elements called 'rare earth metals'. Why?

  1. China, which is the largest producer of these elements, has imposed some restrictions on their export.
  2. Other than China, Australia, Canada and Chile, these elements are not found in any country.
  3. Rare earth metals are essential for the manufacture of various kinds of electronic items and there is a growing demand for these elements.

Which of the statements given above is/are correct?

(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Show answer
Answer: (c) 1 and 3 only