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Relative Permitttivity & Relative Permeability Dependency

  1. May 30, 2012 #1
    Hi Everyone,

    I want to know that is there anyway to relate the relative permittivity (εr) & relative permeability (μr) ???... I am having relative permittivity of an material & i want to find out its relative permeability ...

    Like if εr = 2.2, then μr = ???...

    Please reply ...
  2. jcsd
  3. May 30, 2012 #2


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    welcome to pf!

    hi ubabmar! welcome to pf! :smile:

    if v (= c/n) is the phase velocity of electromagnetic radiation in the material, then …

    ε = εrεo

    µ = µrµo

    εµ = 1/v2

    so εrµr = 1/εoµov2 = (c/v)2 :wink:
  4. May 31, 2012 #3
    Re: welcome to pf!

    Hi Tiny-tim ...
    Thank You for your reply ...
    Yeah, your answer is giving me the relation but if i don't know the 'v' (Phase Velocity of EM radiation) then do this problem has any method ???...
    Please ....
  5. May 31, 2012 #4


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    v is the speed of light in the material …

    (equal to c/n, where n is the refractive index)

    you do need to know it :wink:
  6. Jun 1, 2012 #5
    Thankyou tiny-tim ...
    I got the answer ...
    But a general question that really all the materials posses all these properties ...
    The Parameters are,
    1. Relative Permittivity,
    2. Relative Permeability,
    3. Refractive index.
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