Assertion (A): The Equatorial regions bulge outwards by about 21 kilometre compared to Poles.

Reason (R): Earth’s slow rotation reduces the effect of gravity around the Equator.

Assertion (A) is true: The Earth is an oblate spheroid. Its equatorial radius is approximately 6,378 km, while its polar radius is roughly 6,357 km. This results in a difference of about 21 km, meaning the equatorial region bulges outwards by this amount.

Reason (R) is false: The statement incorrectly describes Earth's rotation at the equator as "slow". In reality, the linear velocity of Earth's rotation is at its maximum at the equator (approximately 1,670 km/h) and gradually decreases to zero at the poles. It is this fast rotational speed that generates a strong outward centrifugal force. This force partially opposes the inward pull of gravity, reducing the effective gravity at the equator and causing the 21 km equatorial bulge. Because it explicitly uses the word "slow", Reason (R) is a false statement.