I Does there exist any electric field inside a charged conductor?

1. May 1, 2017

Anindya Mondal

We know that there exists no electric field inside a conductor. But while calculating drift velocity of electrons inside an electric conductor, why do we consider the electrons are present inside the charged conductor?

2. May 1, 2017

Staff: Mentor

There certainly can exist an electric field inside a conductor. The electric field is proportional to the current density for ordinary conductors. This is known as Ohm's law

3. May 2, 2017

Anindya Mondal

Is it electric field or electric current?

4. May 2, 2017

nasu

Both. The electric field drives the electric current.

5. May 3, 2017

gau55

What you're referring to is probably what you get told in electrostatics at first, but the lack of an electric field is actually the condition for the static state, it can exist and as mentioned here causes a current to flow, this is now electrodynamics

6. May 3, 2017

Paul Colby

On the atomic scale there are always significant electric fields but these average out.

7. May 11, 2017

Anindya Mondal

Yeah, I refer to electrostatics

8. May 12, 2017

vanhees71

In electrostatics by definition you assume that all fields are time independent and that all current densities are vanishing, $\vec{j}=0$. Now you have (in non-relativistic approximation) $\vec{j}=\sigma \vec{E}$, where $\sigma$ is the electric conductivity of your medium. For a conductor $\sigma \neq 0$, which implies that $\vec{E}=0$, because in the electrostatic case you have by definition $\vec{j}=0$.

9. May 14, 2017

Anindya Mondal

I can't understand, please be elaborate.

10. May 15, 2017

vanhees71

What don't you understand? It's very simple. In electrostatics by definition the current density vanishes. In a conductor, according to Ohm's Law, the current density is proportional to the electric field and thus the electric field must vanish within the conductor. I don't know, how I can this elaborate more.