Which one of the following statements is correct?

The acceleration due to gravity (g) is not constant and varies with altitude, depth, and latitude. As altitude increases, the distance from the Earth's center increases, causing g to decrease according to the inverse-square law. Regarding depth, assuming uniform density, g decreases linearly as one moves towards the center because the mass enclosed within the smaller radius decreases. This contradicts option 2. Latitude also affects g; it is greater at the poles and less at the equator due to the Earth's oblate spheroid shape and centrifugal force [2]. Thus, g increases with latitude, making option 3 incorrect. Finally, g is directly proportional to the mass of the Earth (g = GM/R²), so it is not independent of it. Therefore, only the statement that g decreases with altitude is correct.

Sources

1. [2] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 2: The Origin and Evolution of the Earth > Indirect Sources > p. 19