Re: Copper tubing

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-uswest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
> 
> Original poster: "Loudner, Godfrey by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <gloudner-at-SINTE.EDU>

> The high frequency current does not travel on the inside surface of the
> pipe. The situation is more complicated than just saying that the current
> travels on the outside surface of the pipe. The high frequency current will
> travel at the surface of a good conductor, but it makes plunges deeper in to
> the conductor at regular intervals. Think of how a whale swins. The actual
> path of a high frequency current in a conductor is a problem in quantum
> mechanics. 

?! To the observable limits, everything is completely predictable 
with classical electromagnetism. No need of quantum mechanics, or even 
atomic theory. The effect is uniform along the length of the conductor.
Alternating current flows in any conductor with higher concentration at 
the outer surface (or the surface where the magnetic field that
surrounds
the conductor is, what explains what happens at the outer conductor of a
coaxial cable), decaying exponentially with the distance from the 
surface. The distribution depends essentially on the resistitivy of the 
material (deeper for more resistivity) and on the frequency (deeper for
smaller frequency). In coils, current is also reppelled from
the other turns by the same mechanism, in what is called "proximity 
effect".

Antonio Carlos M. de Queiroz