Consider the following statements :
Statement I :
In January, in the Northern Hemisphere, the isotherms bend equatorward while crossing the landmasses, and poleward while crossing the oceans.
Statement II :
In 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?
Show answer
Answer: A. Statement I is correct: in January (northern winter) land cools faster than sea, so isotherms bend towards the equator over land and towards the pole over oceans. Statement II is correct and explains it: the oceans are warmer than the land in January, so the same temperature line is pushed poleward over water and equatorward over cold continents.
Watch for: Students mix up the January and July patterns; in July the bending is reversed.
Why the other options are wrong
- B. Wrong: Statement II is exactly 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.
Source to check: NCERT Class XI, Fundamentals of Physical Geography, chapter 'Solar Radiation, Heat Balance and Temperature' (Distribution of Temperature).
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.