Question

There is a shell of mass \( M \) and density of the shell is uniform. The work done to take a point mass from point A to B is \( [AB = r] \) 
 

• A. \( \frac{GMm}{r} \)
• B. \( \frac{GMm}{R} \)
• C. \( -\frac{GMm}{r} \)
• D. zero

Hint:

For a spherical shell, the gravitational field inside the shell is zero, so no work is done to move an object within it.

Answer 1

The Correct Option is D

Step 1: Understand the work done by the gravitational field.
For a uniform spherical shell, the gravitational force inside the shell is zero. Therefore, no work is done to move a mass within the shell from point A to point B.
Step 2: Conclusion.
The work done in this scenario is zero. Final Answer: \[ \boxed{zero} \]