Question

Assertion: The difference in the value of acceleration due to gravity at pole and equator is due to difference in the latitude of the place.
Reason: The value of acceleration due to gravity is minimum at the equator and maximum at the poles.
A. Both Assertion and Reason are correct, and Reason is the correct explanation for Assertion.
B. Both Assertion and Reason are correct, and Reason is not the correct explanation for Assertion.
C. Assertion is correct, but the reason is incorrect.
D. Assertion is incorrect, but the reason is correct.

Answer 1

Hint: The acceleration experienced by a body due to the gravitational force of the earth is known as acceleration due to gravity. The value of g is independent of the mass of the body and depends only on the mass of the earth and the size of the body.

Complete step by step answer:
As we know, the earth is not spherical but is egg-shaped (oblate). The equatorial radius is about 21km longer than its polar radius. Hence the bodies at the equator are farther from the center of the mass of the earth than the bodies at the poles. The weight of the body increases as the body is taken from the equator to the pole.
We know, ${\rm{g = }}\dfrac{{{\rm{GM}}}}{{{{\rm{R}}^2}}}$
(Where ${\rm{M}}$ is the mass, ${\rm{G}}$is gravitational constant, ${\rm{R}}$is the radius of earth and g is the gravity of earth)
Since, ${\rm{R(equator) > R (pole)}}$
${\rm{g(pole) > }}g({\rm{equator)}}$
Thus, the value of ‘g’ is more at the pole than that at the equator.

Therefore the correct option is (B).

Additional information:
The value of the acceleration due to gravity at the pole is larger than at the equator because the poles are closer to the center of the earth due to the earth's oblate. The measured value is larger because the earth's density is not uniform but increases toward the center.

Note:
Gravity is less at the equator than the pole because there is more centrifugal force at the equator to cancel gravity, your overall weight at the equator versus at the poles is even less. The centrifugal force on your body at the equator is $0.034\;m/{s^2}$ times the mass of your body. The centrifugal force at the poles is zero.