Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Self Inductance

  1. Mar 2, 2009 #1
    1. The problem statement, all variables and given/known data
    Show that the self-inductance per unit length of a wire of radius R carrying a uniform current density inside, the current returning along the surface of the wire is μ0/8π.




    3. The attempt at a solution
    I thought that it might be simpler to calculate the self inductance by 1st calculating the energy stored in the magnetic field round the wire.
    So,

    W = (LI^2)/2 = (1/2μ) ∫ B^2 dV.

    I guess the question implies that the wire forms a circle ( since radius is mentioned ). Now I have problems finding B. I can find B easily in the center of the circle or on axis through the center, but surely I need to find it outside of the circle as well... how do I proceede from here, or do I need to employ a different method.
    Thanks is advance!
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted