Consider the following statements :
Statement-I :
Thickness of the troposphere at the equator is much greater as compared to poles.
Statement-II :
At the equator, heat is transported to great heights by strong convectional currents.
Which one of the following is correct in respect of the above statements ?
Show answer
Answer: A. Statement I is correct: the troposphere is about 18 km thick at the equator and only about 8 km at the poles. Statement II is correct and explains it: strong convection currents at the hot equator carry heat to great heights, lifting the top of the troposphere. So both are correct and II explains I.
Watch for: Some students think the cold poles should have a thicker layer of dense air, but the troposphere is thicker where convection is strongest.
Why the other options are wrong
- B. Wrong because convection is exactly the reason the equatorial troposphere is thicker.
- C. Wrong because Statement II is true; equatorial convection is strong.
- D. Wrong because Statement I is true; the troposphere is thickest at the equator.
Source to check: NCERT Class 11 Fundamentals of Physical Geography, Chapter 7 'Composition and Structure of Atmosphere'
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.