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!

B Electromagnet and a current carrying wire

  1. Dec 27, 2017 #1
    My understanding of an electromagnet is that it is a material with low susceptibility and high permeability, i.e. the magnetic field is not permanent but in the application of a current then the material gets a large magnetic field. In the application of a current the spins of the electrons in the material align in the same direction so the material gets a net "magnetic moment" or magnetic field. I have read on Wikipedia that the magnetic core "focuses" the field caused by the current so the field strength increases by thousands of times. I also know that the current is caused by an electric field drawing the loose valance electrons forward to make a flow of electricity. So my question is this: if you had a hypothetical wire that had in its interior a vacuum, and a shell that no electrons could escape from, could this wire, if wrapped around a material with
    high permeability, generate a magnetic field? I am not sure if the electrons have to escape the wire and go into the magnetic core for the material to get a magnetic field.
  2. jcsd
  3. Dec 27, 2017 #2


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    What do you mean by this ??

    of course not .... that doesn't happen in a normal electro-magnet
    Also the wire of the coil is insulated otherwise the turns of the coil would short circuit
  4. Dec 27, 2017 #3


    Staff: Mentor

    Do you mean a wire with a vacuum-filled hollow core, like a hollow cylinder? There is essentially no difference between that and a regular wire.
    Last edited: Dec 28, 2017
  5. Dec 28, 2017 #4
    Yea that's what I mean.
  6. Dec 28, 2017 #5


    Staff: Mentor

    No, it refers to the type of answer you get. An I answer is likely mathematical. A B answer is mostly in words. I'm going to change this thread to B for you and I cleaned up the posts. Hopefully that might get some good answers for you.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted