UPSC Prelims 2025 · GS Paper I

Question 27: Geography

Consider the following statements :

Statement IIn January, in the Northern Hemisphere, the isotherms bend equatorward while crossing the landmasses, and poleward while crossing the oceans.
Statement IIIn January, the air over the oceans is warmer than that over the landmasses in the Northern Hemisphere.

Which one of the following is correct in respect of the above statements?

aBoth Statement I and Statement II are correct and Statement II explains Statement I

bBoth Statement I and Statement II are correct but Statement II does not explain Statement I

cStatement I is correct but Statement II is not correct

dStatement I is not correct but Statement II is correct

AnswerThe answer is (a).

In January in the Northern Hemisphere the oceans are warmer than the continents, because water heats and cools slowly while land cools quickly in winter. Isotherms therefore bend equatorward over the cold landmasses and poleward over the warmer oceans, so Statement I is correct. Statement II gives the cause and is also correct, and it explains the bending. Remember: in July, the pattern reverses; isotherms bend poleward over land.

I. Isotherms bend toward the equator over land and toward the poles over oceans in January.
II. Oceans are warmer than land in January; this explains Statement I.

How you could have got this

If you were sure Statement I is correct, (d) goes. Then judge the second statement; if it is correct too, decide whether it explains the first.

What you needed to know: Isotherms bend toward the equator over land and toward the poles over oceans in January.

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) Right: both are correct and the warmer oceans explain the poleward bending over them.
(b) Wrong: Statement II is the reason for the bending, so it does explain Statement I.
(c) Wrong: Statement II is also correct.
(d) Wrong: Statement I is also correct.

Explanation: written by UPSC Grade, not by UPSC.

Practise this paper timedPrevious question Next question

Source: UPSC, Civil Services (Preliminary) Examination 2025, General Studies Paper I, Series A. The paper on upsc.gov.in.