On Sat, 08 Apr 2006 22:20:10 -0400, Roger D Johnson
wrote:
I don't understand your statement. Explanation he

http://www.tpub.com/neets/book3/7k.htm

Hi Roger,

Yes, I understood. And from your reference:
"The electrostatic meter movement is actually a large variable
capacitor in which one set of plates is allowed to move. The
movement of the plates is opposed by a spring attached to the
plates. A pointer that indicates the value of the voltage is
attached to these movable plates. As the voltage increases, the
plates develop more torque."

When a current is applied to a capacitor (aka voltage applied, but as
we all know, a current moves charge to those plates), there is a force
developed between the plates (actually in the dielectric) which is
tangential to the plates. This force has the tendency to eject the
dielectric. Our usual experience with capacitors is we rarely have
enough charge AND enough capacitance to measure this effect.

By making one plate movable, the force of the current flow is
expressed in the movement of that plate against a spring (the exact
analogue of opposing magnetic fields, one fixed and the other imparted
by a continuous current flow).

"To develop sufficient torque, the plates must be large and
closely spaced."

That necessary condition of high capacitance; and

" A very high voltage is necessary to provide movement, therefore,
electrostatic voltmeters are used only for HIGH VOLTAGE
measurement."

enough charge to reveal the force.

Your reference is actually

********** W R O N G !! or at least incomplete *************

because what it is describing with two plates in repulsion is NOT a
capacitor (at least not in the conventional sense). This is because
the two plates share the same charge (because they are the same
conductor), hence the repulsion. Further, as this is a variant on the
Leyden Jar, there is another true capacitive plate either in the
nearby structure, or the earth. Otherwise there is no reason for the
charge to flow there in the first place.

73's
Dr. Science (actually, he only has a B.A. in English)