Re: Definition of Capacitance

[Bernard Cleyet <anngeorg@PACBELL.NET>]

I, of course, think the definition of cap. is fine.  Like a bucket the
greater quantity it holds the greater the capacity, logical, n'est pas?
What is required is inverting R;  call it conductance or some such name.

OTOH, one could invert C and call it incapacitance or pac?  (cf. Mho)

bc

Folkerts, Timothy wrote:

> We, as physicists, often seem to be stuck with various conventions and
> definitions.  These conventions are often not the most convenient or most
> logical, but once they get ingrained, they seem almost impossible to adjust.
>
>
> Today's inconvenient convention is capacitance (and I bet I could come up
> with one a day for the next month).  There are two obvious ratios we could
> consider:
>  C  = Q/V
>  C' = V/Q
>
> The first, of course, is the standard definition of capacitance, but the
> second is much more logical because it then matches R & L:
>
> 1) similar definitions:
>  C' = V / Q
>  R  = V / (dQ/dt)
>  L  = V / (d2Q/dt2)
>
> 2) Similar geometry (at least for "standard" geometries):
>  C' =    (1/e0) l/A  (l = length; 1 = one)
>  R  =     (rho) l/A
>  L  = (mu0 N^2) l/A
>
> 3) Similar addition rules:
>  For all three - in series, you simply add values
>                - in parallel, you add inverses.
>
>
> I can't think of a single case where this definition is inferior (except, of
> course, for historical inertia).  Think of all the time and confusion we
> could save our students.  Now we just need to hire a good ad agency and/or
> grease the palms of a few textbook editors ;-)
>
> Tim Folkerts