Re: Series, Parallel, and Resistivity Equations

[Ludwik Kowalski <kowalskiL@MAIL.MONTCLAIR.EDU>]

Referring to Bowman's message:
Brian Whatcott wrote:

> As usual, I found David's insight commanding. THIS time,
> I found it comprehensible too.  You will appreciate this is no
> criticism of David's expositions, but rather of my [lack of]
> mathematical sophistication.

I feel the same way. It is not more difficult to speak about
pipes containing porous medium than to speak of common
pipes. It is true that many students do not know exactly why
a pipe with a porous medium is a better analogy of a wire
with current than an ordinary pipe. But what do we loose by
using a better analogy? Something can be gained from it, for
example, good questions about what corresponds to what,
etc. No analogy is perfect but some are better than others.
That was a good illustration; thanks again David.
Ludwik Kowalski