Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: EM Induction - A conceptual question



Chuck Britton wrote:

ok. I am considering a totally STATIC situation. (A MAJOR shift in
calculations!)

OK, new question requires new answer; see below.

And my question concerns CURRENT that is wrapped enclosed by an
amperian loop. The line integral of B around this loop is s'possed to
equal the current passing through the loop.

THIS consideration makes me scratch my head in responce to:

>The original question described a piecewise-uniform B-field.
>Uniform in one area and zero in another. There's nothing
>mutually-exclusive or inconsistent or unphysical about this.

the line integral of B around the given (amperian) loop is NOT zero
but there is also NO current 'penetrating' the loop!

You gotta read the fine print. The integral in question
is the integral of
B dot dS
^^^
where dS is an element of the loop. It's not |B| times |dS| or
anything like that.

In the specified geometry, B is perpendicular to dS, so
the integral is zero, and there's no problem.