NDA 2026 · PYQ · Gravitation / Potential and Field · medium
For an object in gravitational field, the gravitational potential is the same at two points A and B, but the gravitational field is not the same at these two points. Which one of the following statements is correct?
A.Positive work is done by gravity in moving the object from point A to point B.
B.Negative work is done by gravity in moving the object from point A to point B.
C.Gravity must be non-conservative in such a region.
D.No work is done by gravity in moving the object from point A to point B.✓ Correct
Explanation
The work done by a conservative force such as gravity depends only on the difference in potential between the initial and final points: W = -(U_B - U_A) = -m(V_B - V_A). Since the gravitational potential at A and B is the same (V_A = V_B), the work done by gravity in moving an object from A to B is zero, regardless of the path taken or the value of the gravitational field at those points. The gravitational field being different at A and B does not violate conservativeness — field is the gradient of potential, and equal potential at two points only means the line integral between them vanishes.
💡 Practice unlimited NDA PYQs + AI-tracked progress on each topic. Sign up free →