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Homework Help: EM waves in matter (electrodynamics)

  1. Dec 9, 2009 #1
    I'm having some trouble understanding this module. It would be great if anyone could help.

    In a homogeneous nonconduction region where μr = 1, find εr and ω if

    E=30(pi)e[i(ωt-4/3y)] in z direction

    H=0.1e[i(ωt-4/3y)] in x direction

    I am to understand that for a homognous nonconduction region D=εE and ε=εrε0. However, just equating εr=D/ε0E doesn't seem right. Judging from textbooks and notes I am assuming i must use Maxwell's eqn's for a homogenous nonconducting region, but I'm not sure where to get started. Similarly for ω i can equate ω=(ln|B/10μ0|+4/3y)/t. But again, I'm not sre that this is right.

    If anyone could point me in the right direction that'd be great!
  2. jcsd
  3. Dec 10, 2009 #2


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    Homework Helper
    Gold Member

    There's nothing wrong with saying [itex]\epsilon_r=\frac{D}{\epsilon_0 E}[/itex]...but since [itex]D[/itex] is not given to you, you'll need to express it n terms of the parameters that are given to you in the problem (like [itex]\omega[/itex], [itex]y[/itex] and [itex]t[/itex])...to do that, take a look at what [itex]\mathbf{\nabla}\times\textbf{H}[/itex] is....

    As for finding [itex]\omega[/itex], try calculating [itex]\mathbf{\nabla}\times\textbf{E}[/itex] and compare it to the relevant Maxwell equation...
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