1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Faraday cage in electrodynamics (with currents)

  1. Sep 22, 2016 #1

    Assume a long hollow wire that both carries a nonzero net charge and a current. Is it still true that all charge sits on the outer surface of the cable and that the empty space inside is field-free (Faraday cage)? I know proofs of those facts in electrostatics using Gauss' theorem, but they rely on the fact that there's no electric field inside a conductor, which is not the case in general electrodynamics, for example when there's a current.
  2. jcsd
  3. Sep 22, 2016 #2


    User Avatar
    Homework Helper
    Gold Member

    Right. There's a small driving electric field inside a current carrying conductor because of surface charges.
    This is true only in electrostatic equilibrium.
  4. Sep 23, 2016 #3
    I think that that electric field won't be zero inside the wire ie the hollow part
  5. Sep 24, 2016 #4
    Most examples and experiments of Faraday cages I know appear in dynamic conditions (i.e. with currents): The inside of a car or airplane struck by lightning is save, a radio or cellphone loses reception when wrapped with aluminium foil and so on. Why do they still work under non-electrostatic conditions?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted