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!

Accelerating current

  1. Dec 18, 2011 #1
    Current is simply flow of charge,
    and acceleration of charged particles produces EM radiation.
    Then if we bend a wire,charges(current) would be accelerated as they change direction,then a bent wire must radiate.Is it true?
     
  2. jcsd
  3. Dec 18, 2011 #2

    Bill_K

    User Avatar
    Science Advisor

    Radiation is produced by a changing current, or a changing charge distribution. A steady current does not produce radiation, even in a circular wire.
     
  4. Dec 18, 2011 #3
    When charged particles, electrons, protons etc, are travelling in circular paths in accelerators they produce radiation sometimes know as synchrotron radiation.
    Some synchrotrons are used as sources of X-rays.
     
  5. Dec 19, 2011 #4
    But then even steady current moving in curved path is same as electrons moving in synchrotons.the electrons do radiate so why doesn't the current(which is simply flow of electrons)?

    I am totally confused here?????
     
  6. Dec 19, 2011 #5

    king vitamin

    User Avatar
    Gold Member

    A steady current in a circular wire has a constant charge density throughout. Maxwell's equations gives zero/constant electric field (if the wire is approx. zero charge or charged) and constant magnetic field - no radiation. An electron in a cyclotron does NOT have a constant charge density so the electric field is time dependent. For that matter the magnetic field would be more complicated too!

    The way I understood the first post I imagined bending a wire as charge was flowing through it - in this case there would be radiation of course, since the magnetic field would change.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook