SSC CGL (Prelims) General: Gravitation questions with solutions

Q1. If Earth’s radius shrinks by 1% while its mass remains constant, surface gravitational acceleration would:

1. Rise by about 1%
2. Fall by about 2%
3. Rise by about 2%
4. Fall by about 1%

Answer: Rise by about 2%

Surface gravitational acceleration is given by $g = \frac{GM}{R^2}$. If radius decreases by 1%, then $g$ increases approximately by 2% because of the inverse-square dependence. So the correct option is rise by about 2%.