"Tom Watson" wrote in message
...
I had a conversation with a friend of mine today who has a masters in
electrical engineering.

This degree was conferred by the same school that I went to
(Villanova) about a hundred years ago, so I must inherently trust him.

Yet...

The question that I asked him, which I thought to be simple enough,
was - do the electrons travel down the circumference of the wire, or
do they travel through the core of the wire?

He told me that that is an unknown.

This was very surprising to me as I thought that it would be easily
tested.

Could we not create a wire of a core of inert material and coat it
with a conductor and measure the difference between a wire of the pure
element and that of the coated variety?

This seemed to be not within his reckoning.

The reason that it is important, to me, is that, if the electrons only
travel on the circumference, that circumference may be folded into a
smaller section than that described by the original, and wires would
not have to be so thick.

Would y'all please try to help me out of this conundrum?

Is my friend a poseur?





Regards,

Tom Watson

tjwatson1ATcomcastDOTnet (real email)

http://home.comcast.net/~tjwatson1/

It's been a while, but my remembrance is that as the frequency increases, a
larger portion of the electrons travel on the surface of the wire (skin
effect, see http://en.wikipedia.org/wiki/Skin_effect). So, your idea may
work for high frequencies, but probably not for low frequencies/DC. Some
high frequency circuits (coils, particularly) are built using Lenz wire
(spelling?) which is made up of many strands of very fine wire. Since the
high frequency current flows along the surface, and there's a lot more
surface to the many strands, this bunch of wires can conduct more current
than a single wire of the same outside diameter could.
Real ee's may be able to offer a more correct explanation.
Kerry