RAS question
The Coriolis Effect causes winds to deflect to the _____ in the Northern Hemisphere.
Correct answer: (A) Right.
The Coriolis Effect deflects winds to the right in the Northern Hemisphere.
Explanation
The Coriolis Effect is the apparent deflection of moving air caused by Earth's rotation. NOAA's National Ocean Service explains that if Earth did not rotate, air would circulate between the poles and the equator in a simple back-and-forth pattern. Because Earth does rotate, circulating air does not move in a straight line: it bends to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, producing curved paths. In the Northern Hemisphere, the required direction is therefore "right". The effect is zero at the equator and strongest at the poles, which is why hemisphere and latitude both matter in Coriolis questions.
Why the other options are wrong
- (B) "Upward" is wrong because the Coriolis Effect described here is a horizontal deflection of moving air, not a vertical lift.
- (C) "Left" is wrong for the Northern Hemisphere because leftward deflection applies to the Southern Hemisphere.
- (D) "No deflection" is wrong because Earth's rotation does deflect moving air, with the exception that the effect is zero at the equator.
Concept
This tests the climatology concept of planetary wind movement under Earth's rotation. It recurs in RAS because Coriolis direction is a base rule for winds, pressure belts and ocean-current patterns.