Re: voltages etc.

[Bernard Cleyet <anngeorg@PACBELL.NET>]

"There is a place where it really makes a difference and that is chemical
reference cells.  There you want the equilibrium potential, that is when
no current is flowing, or in other words there is no chemical reaction.

cheers,

joe"

One may "put numbers" on this:    One of my std. cells claimes "internal
resistance not over 500 ohms."   Therefore, one may extrapolate to find
the "true" voltage if one knows the load.  Interestingly, the load while
balancing a pot. is greater than simply using a dime store DMM (10 or 11
meg.)  For example in White and Manning's Exptl. College Physics'
description of the two meter slide wire pot. the protective resistance is
a measly 10k ohms.

My point was the "bald" claim "no current".  Negligible is fine, as JD
defines negligible. [makes no detectable difference, etc.]

bc  who thinks often advances is physics have come from worrying that
negligible wasn't good enuff.

"John S. Denker" wrote:

> Joseph Bellina wrote:
>
> > the point is that when the measurement is finally made the current is
> >  essentially zero....now we can argue about what zero means...I
> > suggest it changes daily with technology.
>
> Right.
>
> Or avoid the need to argue by saying that the
> current is negligible.  That is, even if you
> think the current is nonzero, making it ten
> times bigger or ten times smaller won't have
> any meaningful effect on the quantity of
> interest (the battery voltage).
>
> (If it does have an effect, either your
> battery or your voltmeter is severely broken.)