Re: [Phys-L] interior charge

[brian whatcott <betwys1@sbcglobal.net>]

On 12/29/2013 2:41 PM, rjensen@ualberta.ca wrote:
> Unrelated to the proof, which I assume is possible, I have a few
> questions.
>
> Why are wires round? Why are thicker wires used to carry more current?
> If the charge is on the surface, wouldn't it be better to create the
> wire as a ribbon?
>
> Roy Jensen
I'll try for a response - off the top...
Round wires are a convenient shape to pulltrude, and need marginally 
less insulation for
equal effectiveness compared to insulation for wires of other shapes.
Nevertheless, it is sometimes convenient to
roll conductors of rectangular shapes for close packing in e.g motor 
stators.
Selecting wire cross section is a balance between the temperature rise 
due to current, and the
surface area needed to hold conductor temperature within desired limits.
The current due to quantity of charge carriers moving though a cross 
section is uniform
 within that cross section, in the DC limit.

Brian Whatcott    Altus OK