Question

The difference between the equatorial diameter and polar diameter of the Earth is about
A. 43km
B. 82km
C. 56km
D. 101km

Answer 1

Hint: As we all know that the equator is an imaginary line in the middle of a planet. Equator is an imaginary line that divides the earth into southern hemisphere and northern hemisphere while the Polar diameters are measured from pole to pole.

Complete step by step answer:
From the available mathematical data the equatorial diameter of the earth is about $12756$ km and also the polar diameter of the earth is about $12713.6$ km.

So now to get the difference between the equatorial diameter and polar diameter of the Earth is about, we will subtract the value of the polar diameter of the earth from the equatorial diameter of the earth.
So, we will go as follows:
difference between the equatorial diameter and polar diameter of the Earth
=$(12756 - 12713.6) = 43.6$ km
 If we take the approximate value then the difference between the equatorial diameter and polar diameter of the Earth is about $43$ km.

So, the correct answer is “Option A”.

Note: The equator is at $0^\circ $ latitude and at the half way between south pole and the north pole. The earth is widest at the equator that means the diameter of the earth at the equator is largest. Also the diameter of the earth at the equator is about $43$ km ($27$ miles) times greater than the diameter across pole-to-pole. This also implies that the objects situated at the equator are 21 km away from the earth’s centre (also known as geocentre) than the object which is situated at the poles of the earth.
Here we see that the earth has two different diameters since it is not completely spherical. So, the concept of the mean diameter comes into picture which is the average of the two diameters. So, the mean diameter of the earth is 12,742 km.