Question

Q. With reference to water vapour, consider the following statements:

Which of the statements given above is/are correct?

• A.
  1 only
• B.
  2 only
• C.
  Both 1 and 2
• D.
  Neither 1 nor 2

Answer 1

The correct option is A

1 only

Explanation:

Statement 1 is correct: Water Vapour absorbs not only the long-wave terrestrial radiation (infrared or heat emitted by earth during nights), but also a part of the incoming solar radiation.

Statement 2 is incorrect: Water vapour is also a variable gas in the atmosphere, which decreases with altitude. In the warm and wet tropics, it may account for four per cent of the air by volume, while in the dry and cold areas of desert and polar regions, it may be less than one per cent of the air.