Question

What is angle between electric field and equipotential surface?

• A. $90^{\circ }$ always
• B. $0^{\circ }$ always
• C. $0^{\circ }to90^{\circ }$
• D. $0^{\circ }to180^{\circ }$

Answer 1

Answer: (A)

Potential gradient along equipotential surface is zero.
i.e., $Ecos\theta =-\frac{dV}{dr}=0$
$\therefore \theta =90^{\circ }$