Question

In the northern hemisphere, due to Ferrel’s law the wind is deflected__________.
A) Towards its right
B) Towards its left
C) Towards its north
D) Towards its south

Answer 1

Hint: The flow of air on a large scale from the high-pressure area to low pressure area is referred to as ‘wind'. Earth’s rotation is responsible for the deflection of the circulating air in the Northern as well as the Southern Hemisphere, resulting in curved paths.

Complete answer:
The rotation of our planet produces a force on all bodies moving relative to the Earth. This force is greatest at the poles and least at the Equator because of the Earth’s approximately spherical shape. This force is referred to as ‘Coriolis Force’, caused due to the Earth’s rotation on its axis. Due to this force, the winds in the Northern Hemisphere are deflected towards the right, while the winds in the Southern Hemisphere are deflected towards the left. This is also called Ferrel's law.

If the Earth didn't rotate and stayed still, the atmosphere would circulate between the poles (high-pressure areas) and the equator (a low-pressure area) in a simple back-and-forth manner. But because of the rotation of the Earth, circulating air gets deflected. Instead of moving along a straight path, the air gets deflected toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere, resulting in curved paths.

Earth’s rotation also causes a point at the equator to move faster than a point at higher latitude. Both points make one full rotation in one day’s time, but the point at the equator has to cover a greater distance. The air moving north or south away from the equator toward the poles moves faster than the earth beneath it and the air curves relative to the surface of the Earth.

Thus, the correct answer is Option A. Towards its right i.e. In the northern hemisphere, due to Ferrel’s law the wind is deflected towards its right.

Note: There is no Coriolis effect existing at the Equator. This is because there is no turning of the Earth’s surface (sense of rotation) underneath a horizontally and freely moving object at the equator, there is no curving of the path of the object as measured relative to Earth’s surface. The object’s path is straight, meaning that there is no Coriolis effect.