# Homework Help: Why cant there be an electric field in a conductor?

1. Sep 19, 2007

### indigojoker

why cant there be an electric field in a conductor?

2. Sep 19, 2007

### mgb_phys

Because Maxwell said so!
Short answer is that the fields from each side of a point inside the conductor cancel out - long answer involves a bit of maths.

3. Sep 19, 2007

### antonantal

I guess you are talking about a conductor at equilibrium. In this case the electric field in the conductor is 0 because otherwise the charge (which is mobile in a conductor) would be moving and there wouldn't be equilibrium any more.

4. Sep 19, 2007

### indigojoker

what other cases are there and why would there be an electric field in the conductor?

5. Sep 19, 2007

### antonantal

If there is a net force acting on the charge carriers, the conductor isn't at equilibrium any more. This force could come from a voltage/current source or from a change in the magnetic flux in that circuit.
In this case the electric field in that conductor isn't 0 any more. It is given by Ohm's[/PLAIN] [Broken] law

Last edited by a moderator: May 3, 2017