# The Naked Scientists Forum

### Author Topic: Where does the charge lie  (Read 5881 times)

#### syhprum

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##### Where does the charge lie
« Reply #25 on: 24/09/2009 17:55:58 »
The capacitor would have to be mounted on a track sufficiently far from the dielectric sheet along with its voltage measuring equipment.
After charging it is moved slowly into the vicinity of the dielectric sheet which is drawn between the plates.
by measuring the deflection of the sheet we can calculate how much energy has been transferred to it an see how it corelates to the voltage on the capacitor.
It should be conducted in a very dry atmosphere or vacuum chamber as any moisture on the surface of the dielectric sheet would distort the results.
« Last Edit: 24/09/2009 21:32:19 by syhprum »

#### Geezer

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• "Vive la résistance!"
##### Where does the charge lie
« Reply #26 on: 24/09/2009 19:24:38 »
The capacitor would have to be mounted on a track sufficiently far from the dielectric sheet along with its voltage measuring equipment.
After charging it is moved slowly into the vicinity of the dielectric sheet which is drawn between the plates.
by measuring the deflection of the sheet we can calculate how much energy has been transferred to it an see how it corelates to the voltage on the capacitor.
It should be conducted in a very dry atmosphere or vacuum chamber as an moisture on the surface of the dielectric sheet would distort the results.

Good points!

I think the dielectric should probably have the same dimensions as the plates - for example, all circles of equal diameter. Also, rather than use a track to support the plates, the plates could travel in an arc around the same center as the dielectric "pendulum". This should allow us to observe the maximum angular deflection.

Considering the question about "where did the energy go?", if this experiment works, it would seem to prove that the "missing" energy is stored in the dielectric. When the dielectric is removed, the energy that was stored in it is returned to the plates, or is that an over simplification?

#### syhprum

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##### Where does the charge lie
« Reply #27 on: 24/09/2009 20:29:39 »
a very similar experiment to this was carried out 150 years ago,it was found that provided the dielectric was quite dry it did not carry away the charge but if there was any possibility of a slight film of moisture on it it did.

A charged 'Leyden jar' (a cylindrical capacitor with a glass dielectric) was dismantled and the glass was fitted into a fresh jar, if the glass was not perfectly dry the charge was transferred but if it was dry it was not.

This is a quote from my 1920,s school book on electrostatics

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##### Where does the charge lie
« Reply #27 on: 24/09/2009 20:29:39 »

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