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Homework Help: Intrinsic Wave Impedance for Conductive Medium

  1. Nov 6, 2011 #1
    1. The problem statement, all variables and given/known data
    I know that for air, the intrinsic impedance η is 377 Ω, but it becomes complex in a conductive medium. This fact is sort of hindering me in being able to answer a few problems consisting of electric and magnetic waves in a conductive medium, but I just wanted to clarify one thing.
    Say, I am given H(z,t)=0.5cos(ωt-βz)ay+0.7cos(ωt-βz)ax

    2. Relevant equations
    I know that the intrinsic impedance for a conductive medium is:
    attachment.php?attachmentid=40735&stc=1&d=1320639186.png

    3. The attempt at a solution
    When σ=0 for one problem, I was left with:
    attachment.php?attachmentid=40736&stc=1&d=1320639330.png
    But I do know that
    attachment.php?attachmentid=40738&stc=1&d=1320639449.png

    My question is, what in the world is u_o, ε_o, and ε_r ???
    Am I supposed to figure this out or is this already provided in a table somewhere?
    I have been trying to look in my book and online, but am getting confused easily.
    Will someone please clarify this for me?
    Any help is greatly appreciated!
     

    Attached Files:

  2. jcsd
  3. Nov 7, 2011 #2

    rude man

    User Avatar
    Homework Helper
    Gold Member

    Those are all real constants. mu_0 and epsilon_0 are permeability and permittivity of free space, look them up anywhere, and epsilon_r is the relative permittivity of your medium (= epsilon/epsilon_0).

    How you got as far as you did, which is pretty far, without knowing that is a bit of a mysrtery to me, and please believe that I'm nort trying to be condescending or insulting - just wondering!
     
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