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!

Newbie Problems on Electrodynamics

  1. Aug 26, 2004 #1
    May anyone please show me how to derive the "magnetic field energy density" in a medium, which equals [tex]\frac{1}{2}H \cdot B[/tex]?

    I would be very pleased if anyone could show me how to derive (step-bystep) the conservation of energy equation *in a medium* (not in vacuum) i.e. [tex]\nabla\cdot S + \frac{\partial v}{\partial t} = -E \cdot J [/tex], where [tex]v = \frac{1}{2}(E \cdot D + B \cdot H)[/tex] and S is the poynting vector. (N.B. The medium may not be linear i.e. D may not be proportional to E, H not to B)
    Last edited: Aug 26, 2004
  2. jcsd
  3. Aug 26, 2004 #2
    Sorry for asking....I understand now, that the equation I posted only works for linear quasistatic media. Thus D should be proportaional to E and H to B and the derivation is essentially the same as in the vacuum case.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Newbie Problems on Electrodynamics
  1. Electrodynamic doubt (Replies: 10)