Assertion: Electric field is aways directed perpendicular to an equipotential surface.
Reason: Equipotential surface is a surface on which at each point potential is same.

Options

A. Statement I is true, Statement II is True, Statement II is a correct explanation for statement I.
B. Statement I is true, Statement II is True, Statement II is Not a correct explanation for statement I.
C. Statement I is True, Statement II is False.
D. Statement I is False, Statement II is True.

Answer

B

Explanation

On an equipotential surface, the potential at each point is same throughout. Let `vecE` be electric field at a point on and equipotential surface. Then, small work done in moving a test charge `q_(0)` though a small displacement along the surface is `dW=vecE.vecdr=(q_(0)vecE).vecdr` ltbgt Since work in moving a test charge along an equipotential surface is always zero `(-q_(0)vecE).dvecr=0` or `vecE.dvecr=0`. Hence electric field is directed perpendicular to the surface