Magnetic Field around a dipole calculation

  1. 1. The problem statement, all variables and given/known data
    I've attached a page from the book Elements of Electromagnetics.

    I was wondering how he gets from eq.8.20 to eq.8.21a.

    What I would have done is sub in dl=a.d∅.a∅ and integrate ∅ between 0 and 2pi.

    This would then give you A=[(2.μ0.I.pi.a)/(4.pi.r)].a

    This is obviously wrong because it's not what he got. He does make an assumption that r>>a so maybe i have to do something with that.

    Any help would be much appreciated

    Thanks
     
  2. jcsd
  3. I think i forgot the attachment
     

    Attached Files:

  4. Its ok, i found the explanation in a book on google books. Its a bit long and tedious.

    I guess no one here would be able to understand it which is why i got no reply. Oh well...
     
Know someone interested in this topic? Share a link to this question via email, Google+, Twitter, or Facebook