Re: Faraday induction

[brian whatcott <inet@INTELLISYS.NET>]

At 16:37 5/30/01 -0400, Wolfgang wrote:

> > In contrast, the original question cited a "rule" about
> > the induced _current_ .  That does not apply in this case, for
> > the simple reason that there never was any such rule.
> >
> > You can calculate the induced current (or lack thereof)
> > from the given Maxwell equation and Ohm's law.  No problem.
> >
> > If (!) there is an induced current, Lenz's law is a useful
> > rule of thumb, a mnemonic that helps you keep the signs
> > straight, so you know the direction of the current.
> > That's all.  It doesn't say there will be a current.
>
> I didn't mean to imply that there was a current but merely that the induced
> emf could produce a current (if there were a complete circuit).  In fact,
> we were using the law, as you suggest, to determine which end of the loop
> will end up with a higher potential w.r.t. the other end.
>
> Wolfgang


It seems to me that if Wolfgang did not mean to imply there is a current
in a ring conductor with a gap, he should have. There is a curious
polarization of a conductor with an accompanying displacement current in
a time or space-varying magnetic field. If I recall, this exercised
Einstein's imagination.


brian whatcott <inet@intellisys.net>  Altus OK
                Eureka!