UPSC Prelims 2012 · Question 14 of 98

UPSC Prelims 2012 question on Graphene Properties

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?

  1. 1 and 2 only
  2. 3 and 4 only
  3. 1, 2 and 4 only
  4. 1, 2, 3 and 4
Show answer

Answer: C. 1, 2 and 4 only

Verdict

Correct Answer: 1, 2 and 4 only

Statements 1, 2 and 4 are correct because graphene is a highly conductive, extremely thin and strong carbon material useful in transparent electronic electrodes, while Statement 3 is incorrect because it is not made of silicon.

Analysis

Graphene is a one-atom-thick, two-dimensional allotrope of carbon. It is known for its high electrical conductivity, strength, flexibility and transparency.

Statement by statement

1. It is a two-dimensional material and has good electrical conductivity — Correct

Graphene is a two-dimensional sheet of carbon atoms arranged in a hexagonal lattice.

It has excellent electrical conductivity and is considered useful in advanced electronic applications.

2. It is one of the thinnest but strongest materials tested so far — Correct

Graphene is only one atom thick, making it extremely thin.

Despite this, it is very strong and is often described as much stronger than steel by weight.

3. It is made of silicon and has high optical transparency — Incorrect

Graphene has high optical transparency, but it is not made of silicon.

It is an allotrope of carbon. The silicon part makes the statement incorrect.

4. It can be used as conducting electrodes required for touchscreens, LCDs and organic LEDs — Correct

Graphene’s conductivity, transparency and flexibility make it suitable for transparent conducting electrodes.

It can be used in touchscreens, LCDs, organic LEDs and other flexible electronic devices.

Extra UPSC info

* Graphene was isolated in 2004.

* The 2010 Nobel Prize in Physics was awarded for groundbreaking work on graphene.

* It is an allotrope of carbon, like diamond, graphite and fullerenes.

* Major applications include batteries, supercapacitors, sensors, water filtration and flexible electronics.

* Large-scale, low-cost production remains a major challenge.

* Do not confuse graphene with silicon-based materials; graphene is carbon-based.

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