Consider the following statements : 1. The winds which blow between 30° N and 60° S latitudes throughout the year are known as westerlies. 2. The moist air masses that cause winter rains in North-Western region of India are part of westerlies. Which of the statements given above is/are correct?
- (a) 1 only
- (b) 2 only ✓ UPSC's answer
- (c) Both 1 and 2
- (d) Neither 1 nor 2
Why the answer is (b)
• Statement 1 is wrong: westerlies blow between 30° and 60° latitude in each hemisphere (30°–60° N and 30°–60° S); 'between 30° N and 60° S' would include the tropics and the trade-wind belts.
• Statement 2 is correct: winter rain in north-west India comes from western disturbances — extra-tropical cyclones from the Mediterranean carried east by the sub-tropical westerly jet — which are part of the westerly circulation.
• Hence 2 only, option (b).
Why the other options are wrong
- (a) 1 only
- Statement 1 is wrong: the latitude range is misstated.
- (c) Both 1 and 2
- Statement 1 is wrong.
- (d) Neither 1 nor 2
- Statement 2 is correct: western disturbances are westerly.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2015, held on 23 August 2015. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.