Why charge is zero inside a conductor


When we find electric field for a conductor having closed surface, then we take charge inside conductor zero, because in conductor charge comes on surface due to force between charges. This is what I have studied.

But for an ideal conductor, permittivity is infinite so electrostatic force must be zero inside conductor, then how charges come on surface?

Best Answer

The electrostatic field is zero AFTER equilibrium is established (after the internal E-field cancels the external E-field.)

Remember the equation that describes the introduction of charges at some interior point of a given material:

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What it means is that any charge introduced at the interior of the conductor will decay immediately and appear on the the surface.

Stated in other way, if some charges are introduced in the interior of a conductor, the charges will move to the surface and redistribute themselves quickly in such a manner that the field inside the conductor vanishes.