Question

Hi, could someone explain why the surface of a conductor is always equipotential? Thank you!

Answer 1

As long as potential difference is not zero, free electrons on the surface experience force and drift. In the static situation, the free electrons have so distributed themselves that the tangential component of electric field is zero everywhere on the surface. E is always radial.

so no work is done in moving a test charge on surface of conductor. so no change in potential on the surface..

Answer 2

Thank you.
"In the static situation, the free electrons have so distributed themselves that the tangential component of electric field is zero everywhere on the surface."
Could you further explain this? Is there a law for this phenomenon? Thanks again!

Answer 3

@funtowrite Static means there is no motion. If electrons are not distributed enough, then electrons will push each other, which make motion of electrons. Consequently, they push and push each other and eventually the electrons will feel same amount of electric field in all direction in conductor and stop moving. So the amount of electric field in tangential direction will be same and the sum will be 0.

Answer 4

exactly..

funto : maybe first ponder on why electric filed inside a conductor is zero everywhere. once you digest that concept, it becomes easy to visualize about electric field direction on surface...