1
\$\begingroup\$

I'm learning about current in conductors, and came across the statement that "The electric field inside a perfect conductor is zero", this is frequently explained used Gauss´s Law by saying that the contained charge is zero since all the charge is distributed along the surface, also the other way of explaining it is by saying that an internal electric field is produced and neutralizes the external electric field. Such as in the image:

enter image description here

I get the point as some sort of abstraction in order to understand this behavior, but as far as I've heard electrons and charged particles in general move really slow so in order to be placed as in the image it would take some, and maybe a considerable amount of time, so is there something happening meantime or do charges instantly get moved to the surface and placed as in the picture?

\$\endgroup\$
2

1 Answer 1

1
\$\begingroup\$

The drift speed of electrons is irrelevant here.

Assume you magically turn on the external field instantly. That leads to charge carriers at the surface to redistribute, form small dipole moments locally. That of course has an effect on the neighboring charge carriers, which locally counter the field, neutralize, and so on. There's going to be a wave rolling through the material of locally neutralizing the field.

Note that while your material is theoretically infinitely conductive, magnetic material properties still exist and limit the speed of neutralization below the speed of light in vacuum, because they limit the amount of replacement current that can flow instantly after turning on the stimulus.

\$\endgroup\$
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.