UPSC Prelims 2011 · GS Paper I
Question 52: Geography
La Nina is suspected to have caused recent floods in Australia. How is La Nina different from El Nino ?
- 1.La Nina is characterised by unusually cold ocean temperature in equatorial Indian Ocean whereas El Nino is characterised by unusually warm ocean temperature in the equatorial Pacific Ocean.
- 2.El Nino has adverse effect on south-west monsoon of India, but La Nina has no effect on monsoon climate.
Which of the statements given above is/are correct ?
AnswerThe answer is (d).
La Nina is the cooling counterpart of El Nino in the equatorial Pacific: unusually cold sea surface in the central and eastern Pacific, while El Nino is unusual warming there. Statement 1 wrongly puts La Nina in the Indian Ocean. Statement 2 is also wrong, because La Nina does affect the monsoon, generally favouring good Indian rainfall, just as El Nino is linked to weak monsoons. So both statements are incorrect.
- 1. La Nina is cooling in the equatorial Pacific, not the Indian Ocean.
- 2. La Nina does influence the monsoon, usually favourably.
How you could have got this
- If you were sure statement 1 is not correct, (a) and (c) go: each of them includes 1.
What you needed to know: La Nina is cooling in the equatorial Pacific, not the Indian Ocean.
- Then, if you were sure statement 2 is not correct, (b) goes: it includes 2.
What you needed to know: La Nina does influence the monsoon, usually favourably.
Only (d) is left. This one needs every statement.
This follows an unofficial answer: UPSC has not published its key for this year, and if that answer is wrong, so is this path.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Statement 1 wrongly places La Nina's cold water in the Indian Ocean.
- (b) Statement 2 is wrong: La Nina does influence the monsoon.
- (c) Neither statement is correct.
- (d) Right: both statements are incorrect.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2011, General Studies Paper I, Series A. The paper on upsc.gov.in.