2015 GS Paper I, all questions
UPSC Prelims 2015 · GS Paper I
Question 14: Geography
What explains the eastward flow of the equatorial counter-current?
aThe Earth's rotation on its axis
bConvergence of the two equatorial currents
cDifference in salinity of water
dOccurrence of the belt of calm near the equator
AnswerUPSC’s answer is (b).
The North and South Equatorial Currents flow westward under the trade winds and pile warm water up on the western side of the ocean. This raises the sea level there, and the water flows back eastward down the slope along the belt between the two currents, as the equatorial counter-current. UPSC's explanation is the convergence of the two equatorial currents. Remember: the counter-current is a return flow.
Why each option is right or wrong
- (a) Earth's rotation drives the westward equatorial currents; it does not explain the eastward counter-current.
- (b) Correct: the two equatorial currents converge and pile up water in the west, which flows back east.
- (c) Salinity differences cause density currents, not the main flow of the counter-current.
- (d) The doldrums are a calm belt where it flows; calm air does not drive it.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2015, General Studies Paper I, Series A. The paper on upsc.gov.in.