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!

Multipole expansion of point charge placed inside a cube

  1. Sep 29, 2012 #1
    1. The problem statement, all variables and given/known data

    A cube of side a is fi lled with a uniform charge density distribution of total charge Q. A point
    charge +Q is placed at the center of the cube.

    Show all odd electrostatic multipole moments vanish. (i.e., 2^l poles with odd l). Show that
    among the even moments, those with l = 0; 2, vanish.

    2. Relevant equations

    Classical Electrodynamics, Jackson 4.3

    http://tinypic.com/view.php?pic=wh4z5&s=6

    3. The attempt at a solution

    I can't seem to figure out how to go about this. There's two main things that I'm stuck with:

    How to deal with the point charge within the cube

    How to solve the multipole moments in cartesian (Jackson)

    I believe I would have to split the integrals into two parts where one goes from 0 to the cubes surface and the other goes from the cubes surface to infinity but it doesn't seem to be working out.

    I've been trying to find an example of solving the multipole moments in Cartesian and finding the moments of a volume with a charge in the middle but I've had no luck.

    Any help with this is greatly appreciated.
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?



Similar Discussions: Multipole expansion of point charge placed inside a cube
Loading...