Re: Lenz's Law?

[Chuck Britton <britton@odie.ncssm.edu>]

> Tom McCarthy
> Saint Edward's School
> 1895 St. Edward's Drive
> Vero Beach, FL  32963
> 561-231-4136
> Physics and Astronomy

> > And cooling the ring in LN2 is an exciting way to show the
> > decreased resistance at lower T for most metals, as well as >illustrating
> Ohm's Rule of Thumb that the lowered resistance results >in a greater
> current being created by the changing magnetic flux.        >(Faraday's Law
> of Induction).
>
> How do you monitor the difference between room temperature and LN
> temperature currents?
	The cold ring flys further, faster, showing a greater current =>
greater opposing magnetic field.

> > The demos of this that I have seen only send a single pulse of >current
> thru the coil, making the Lenz's Law explanation more >beleivable.
>
> Since the ring goes flying high at the onset of the switch, wouldn't this
> qualify as the effects of a single pulse?

	I reckon the ring leaves the pole in less than 4 ms or so, before
the next half cycle has a chance to complicate things.