You can measure viscosity by measuing the time taken for oil to drain
through a tube ( at least I've always assumed that's why heating oil is
graded in "seconds")
I wonder if you could measure capacitance (or charge) be measuing the time
taken for oil to drain out from between the vanes of a capacitor ?
There are probably less messy ways of measuring it :-)
Hugh
PS Yes, we had a KiloVolt meter like a free-turning variable capacitor in
the school physics lab I remember ...
----- Original Message -----
From: "Johan Bodin" <[email protected]>
To: <[email protected]>
Sent: Friday, November 08, 2002 12:36 PM
Subject: LF: Re: Re: To Ponder over the weekend
g6tmk wrote:
My guess is the 10uF capacitor becomes 1uF and the voltage rises to 100V.
That's my guess too, but... W [stored energy] = V^2*C / 2:
With oil: V=10V, C=10u => W = 10*10*10u / 2 = 500 uJ
Without oil: V=100V, C=1u => W = 100*100*1u / 2 = 5000 uJ
Assuming that no charge goes away with the oil, the stored energy
will increase by a factor of ten. Hmm... Force * distance = energy.
When gravity pulls the oil away from the plates, the oil has to fight
against an electrostatic force thereby injecting energy into the
capacitor, I guess...
Will a charged air variable capacitor try to turn itself towards
the maximum setting? :-)
73
Johan SM6LKM
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