Re: [Phys-l] A scaling problem?

[brian whatcott <betwys1@sbcglobal.net>]

On 12/20/2011 11:23 PM, Bernard Cleyet wrote:
> Bill Layton has demonstrated this app., but asks first:   Which wire will glow first?
>
> The app. is three same length and resistivity connected in parallel and different diameter Ni-Cr wires   The first time he used a Pb-acid accumulator; more recently a step down transformer and variable auto transformer powered by the domestic mains.
>
>
> So I ask you-all.
>
>
> bc
That the question is asked at all is an alert that there is something
 counter-intuitive about the setup.
So then we ask: WHY should the thickest nichrome wire glow first?
It is dissipating most power naturally, and oh, it has least dissipation
surface area per unit power dissipated. The question then becomes:
 why wouldn't the thickest wire in the parallel setup glow first?

Brian W