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Re: Conserving Q/Faraday



Ludwik,
If you disassemble the discharged capacitor inside the Faraday cup (with
attached electrometer) and remove the plates one at a time, when does the
electrometer show a non-zero reading?

Bob Sciamanda
Physics, Edinboro Univ of PA (ret)
trebor@velocity.net
http://www.velocity.net/~trebor

-----Original Message-----
From: Ludwik Kowalski <KowalskiL@MAIL.MONTCLAIR.EDU>
To: PHYS-L@LISTS.NAU.EDU <PHYS-L@LISTS.NAU.EDU>
Date: Monday, January 25, 1999 11:44 PM
Subject: Re: Conserving Q/Faraday


WE NEED ADVICE

. . . . .
3) HERE IS MY QUESTION. Suppose that a net charge is really
present in the dielectric slab of a capacitor connected to HV. How
can this net charge possibly be revealed? A naive approach was
to disconnect C from the power supply, discharge it and stick it
(without dissecting) into the Faraday cup. By doing this we always
find that the net Q is zero. But this refers to the sum of charges
on three objects (the dielectric slab and two electrodes), not to
the Q in the dielectric slab alone. The discharged electrodes are
not necessary neutral, they may have + and - charges induced by
the layers of the remaining bound charges in the dielectric. If so
then the net Q in the electrodes compensates the net Q in the
dielectric.

. . . . .
Ludwik Kowalski