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Homework Help: Write down a list of nine features of the radiation fields that can be deduced

  1. Dec 21, 2011 #1
    1. The problem statement, all variables and given/known data

    In the limit of large distances, the electric field that is associated with the radiation magnetic fields is given by the real part of:

    E(r)=[(μ(subscript 0) I(subscript 0) δ l)/(4pi)] cos θ ((-i ω)/r)exp [i(kr-ωt)] θ-hat

    The magnetic field is given by the real part of:

    B(r)=[(μ(subscript 0) I(subscript 0) δ l)/(4pi)] sinθ [((-i ω)/(rc))+(1/(r^2))]exp [i(kr-ωt)] phi-hat

    Write down a list of up to nine features of the radiation fields that can be deduced from the form of the expressions for the radiation B and E fields. You should consider the relationship between E and B, the factors determining the amplitude of the wave, the polarisation of the wave, the speed of the wave and the shape of the waveform.

    3. The attempt at a solution

    E and B are perpendicular to each other.
    They are travelling in the same direction.
    They both have a sinusoidal shape.
    They have different amplitudes.
    They are linearly polarised.

    That's all I can think of. Please help me think of some more.

    How do I deduce the speed of the wave from those equations?
     
  2. jcsd
  3. Dec 30, 2011 #2
    E is travelling in the theta-hat direction.
    B is travelling in the phi-hat direction.

    But I am really stuck on thinking up two more features to answer the question. Please help.
     
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