1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Approximation of linear quadrupole as a dipole in radiation zone

  1. May 29, 2008 #1
    Hello,

    This question is more conceptional - I think I can do the algebra (mostly approximations) in this problem ok.

    1. The problem statement, all variables and given/known data

    I am wondering why it is for a radiation zone, that a linear electric quadrupole can be approximated as a dipole. I am wondering if this is just a coincidence or if this is a specific case due to an intrinsic geometry or a characteristic about radiation zones that allows us to do this.

    I doubt it is coincidental - if it were, I would guess that higher order dipoles (meaning bigger than quadrupoles) can be approximated as such then - that doesn't make sense to me.

    There must be something "special" about radiation fields that allows us to say this: does this have to do with the energy density then? Maybe the magnitude of the Poynting vector? Perhaps the amplitude of the wave oscillation in the B-field in the radiation zone...(But what would dipoles/quadrupoles have to do with this then?)

    Anything clarification would be greatly appreciated. Thanks so much! Take care.

    --Doris


    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you help with the solution or looking for help too?



Similar Discussions: Approximation of linear quadrupole as a dipole in radiation zone
Loading...