KVPY2020PhysicsGravitation
At a height of 10   km above the surface of earth, the value of acceleration due to gravity is the same as that of a particular depth below the surface of earth. Assuming uniform mass density of the earth, the depth is,
Options
- A1   km
- B5   km
- C10   km
- D20   km
Correct answer
D. 20   km
Step-by-step solution
At a height h g h = g 0 1 - 2 h R when h ( 10   km ) < R ( 6400   km ) at a depth d g d = g 0 1 - d R here g 0 = G M R 2 Now g h = g d ⇒ d = 2 h d = 20   km