Question

Why the value of g is greater at poles than at the equator

Answer 1

as we know, the shape of the earth is not actually a perfect sphere... the distance of the poles to the core is closer than that of the equator... the closer the distance, the greater the value of g (acc due to gravity)

Answer 2

First of all, 'g' is greater at equator than the poles.This is due to the shape of the earth.The earth is flattened a bit at the poles. This affects the radius of the earth at the poles.The radius of earth at the poles is less than that at the equator.And as we know that the value of 'g' depends upon the radius of earth(or any other planet), the more the radius the more the value of 'g'. Hence, it is greater at the equator than the poles(Since radius is grater at the equator).