Question

Which of the following is not the property of equipotential surfaces?

• A. They do not cross each other
• B. They are concentric spheres for uniform electric field
• C. Rate of change of potential with distance on them is zero
• D. They can be imaginary spheres

Answer 1

Answer: (B)

They are concentric spheres for uniform electric field

Answer 2

There is no potential gradient along any direction parallel to the surface. Any surface over which the electric potential is same everywhere is called an equipotential surface. The electric field and hence, lines of force everywhere are at right angles to the equipotential surface. This is so, because there is no potential gradient along any direction parallel to the surface and, so no electric field parallel to the surface. This means the electric field and hence, lines of force are always at right angles to the equipotential surface. Hence, they are not concentric spheres for uniform electric field. They are concentric spheres for an isolated point charge. Rest option (a), (c), (d) are properties of equipotential surface.