From: John Woodgate
Subject: Re: Problem with magnetic boundary conditions
Date: Fri, 13 Dec 2002 22:26:37 +0000
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Fri, 13 Dec 2002 22:54:14 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Chris Carlen
wrote (in ) about 'Problem with magnetic boundary
conditions', on Fri, 13 Dec 2002:
>My problem is that the Biot-Savart law which is used to calculate
>magnetic field strength H at an arbitrary point in space due to the
>current flowing in a conductor, pays no attention to the permeability of
>the medium, and thus it does not lead to the conclusion that there is a
>step discontinuity in the normal component of H crossing the boundary.
But it *assumes* a homogenous medium. At least Ampere's/Laplace's
Theorem does, and it is an alternative statement of B-S, AIUI.
>I can understand arguing from the starting point of B, that H must go as
>u1 H1n = u2 H2n, but the Biot Savart Law says that H is continuous.
In a homogenous medium.
>think. Unfortunately the calculations using the Biot-Savart law are
Really? What calculations are you thinking of? Maybe Ampere/Laplace
would give you simpler calculations.
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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