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Homework Help: Electromagnetism problem

  1. Sep 28, 2006 #1
    How does one calculate the reflection coefficient for light at an air to silver interface at optical frequencies ([tex]\omega = {4 *10^{15} s^{-1}}[/tex])
    given

    [tex]\mu_{I} = \mu_{T} = \mu_{0} , \sigma = {6 * 10^7 mhom^{-1}}[/tex]
     
    Last edited: Sep 28, 2006
  2. jcsd
  3. Sep 29, 2006 #2

    Meir Achuz

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    The reflection is close to 100% for silver.
    the reflected intensity is I_r=I_0-I_absorbed.
    [itex]I_{absorbed}=\sqrt{\omega/8\pi\sigma}I_0[/itex] in Gaussian units.
     
  4. Sep 29, 2006 #3
    Would this work?

    Knowing the frequency means we can find the wavelength clearly, which has units metres, clearly. When combined with [tex]\sigma = {6 * 10^7 mhom^{-1}}[/tex] to get the impedance of the silver. Then taking the ratio with the impedance of free space and assuming normal incidence

    [tex]r =\frac{1 - \beta}{1 + \beta} [/tex]

    where [tex]\beta = \frac{\eta_0}{\eta_s} [/tex]

    Would this work?
     
    Last edited: Sep 29, 2006
  5. Sep 30, 2006 #4

    Meir Achuz

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    How would you calculate \eta?
     
  6. Sep 30, 2006 #5
    eta_s is the impeance of silver. As indicated previously a value with ohm units can be achieved by combining wavelength with the value of conductivity. What im asking is, is this a valid statement?
     
  7. Oct 1, 2006 #6

    Meir Achuz

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    No. Units are not a calculation.
     
  8. Oct 1, 2006 #7
    i want to know about the motion of the stelites totely
     
  9. Oct 1, 2006 #8
    basic defination of electromagnatic physics
     
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