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The work done in moving a positive charge along an equipotential surface is:

1. Finite, positive but not zero
2. Finite, negative but not zero
3. Zero
4. Infinite

Correct answer: Zero

Solution

All points on an equipotential surface have the same potential, so the potential difference between any two points on it is zero. Work done = q * (V_final - V_initial) = q * 0 = 0.

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