Inside a uniform spherical shell :
(1) the gravitational field is zero
(2) the gravitational potential is zero
(3) the gravitational field is same everywhere
(4) the gravitational potential is same everywhere
(5) all of the above
Choose the most appropriate answer from the options given below :

Solution

Physics sir · 4 steps

Inside the shell the field is zero, so the potential stops changing, but it does not drop to zero.

1. Field inside. By Gauss's law for gravity, a surface drawn inside the shell encloses no mass, so the field there is E = 0. It is zero at every inside point, so it is also the same everywhere.
2. Potential inside. Field and potential are linked by E = -dV/dr. If E = 0 inside, then V does not change with r, so the potential is the same at every inside point.

   V_(inside) = -GM/R

3. Not zero. The constant value equals the potential at the surface, -GM/R, which is not zero. So statement (2) is false, and (5) falls with it.
4. So. Statements (1), (3) and (4) are true, which is option (a).

The idea to keep. Zero field means constant potential, not zero potential. Inside a shell, V stays fixed at its surface value -GM/R.

Answer from the NTA final answer key. Solution by PrepWiser.