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!

Qausi-static displacement current (Purcell)

  1. Jan 4, 2012 #1
    "Qausi-static" displacement current (Purcell)

    Hello all,
    On page 329, chapter 9 of Purcell's E&M book, he describes why the "displacement current" produces nearly zero magnetic field for slowly varying fields. By taking the curl of the displacement current Jd, he shows that curlJd=-(1/4[itex]\pi[/itex]c)(∂2B/∂t2), so that for slowly varying fields, curlJd is nearly zero. From this, using a symmetry/superposition argument he concludes that there can be no magnetic field for such a current distribution. It is this last step that I do not understand; how does curlJd=0 imply B=0?
  2. jcsd
  3. Jan 5, 2012 #2
    Re: "Qausi-static" displacement current (Purcell)

    Bump? Maybe this belongs in the classical physics section?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook