RAS question
Coriolis effect causes:
Correct answer: (D) Deflection of winds to the right in Northern Hemisphere and left in Southern Hemisphere.
The Coriolis effect deflects winds to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
Explanation
The Coriolis effect is the apparent deflection of moving air caused by the Earth's rotation. NCERT describes it as the force by which the rotation of the Earth affects wind direction: winds are deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. NCERT also explains the latitude link behind this pattern: the Coriolis force is absent at the equator, increases with latitude, and is maximum at the poles. That is why option D captures the core effect. The equatorial zero also explains why tropical cyclones do not form near the equator; the low-pressure area gets filled instead of intensifying into cyclonic circulation.
Why the other options are wrong
- (A) Hurricanes are not produced in all regions, because the Coriolis force is absent at the equator and tropical cyclones do not form near it.
- (B) The Coriolis effect changes wind direction by deflection; it does not make winds always move from west to east.
- (C) No deflection at the equator is true, but it states a special case rather than the main hemispheric deflection caused by the Coriolis effect.
Concept
This tests the physical geography concept of atmospheric circulation, especially how Earth's rotation modifies wind movement. It recurs in RAS because the same principle explains pressure belts, trade winds, geostrophic winds and tropical cyclone formation.