With reference to "Coriolis force", which of the following statements is/are correct ? 1. It increases with increase in wind velocity. 2. It is maximum at the poles and is absent at the equator. Select the answer using the code given below :
- (a) 1 only
- (b) 2 only
- (c) Both 1 and 2 ✓ UPSC's answer
- (d) Neither 1 nor 2
Why the answer is (c)
• The Coriolis force is an apparent force arising from the Earth's rotation; it deflects moving air and water to the right in the Northern Hemisphere and to the left in the Southern.
• Statement 1 is correct: its magnitude is proportional to the speed of the moving body, so faster winds are deflected more.
• Statement 2 is correct: it also depends on the sine of latitude — zero at the equator and maximum at the poles — which is why tropical cyclones do not form within about 5° of the equator.
• The force acts perpendicular to the direction of motion, changing direction but not speed.
• Hence both 1 and 2, option (c).
Why the other options are wrong
- (a) 1 only
- Statement 2 is also correct: the force is zero at the equator and maximum at the poles.
- (b) 2 only
- Statement 1 is also correct: the force rises with wind speed.
- (d) Neither 1 nor 2
- Both statements correctly describe the Coriolis force.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2024, held on 16 June 2024. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.