Robin is right, in a parallel plate capacitor C=epsilon*A/d so q (constant here) = C*v = (epsilon*A/d)*v = epsilon*A * v/d
so v/d is constant too. Michel ----- Original Message ----- From: "John Berry" <[EMAIL PROTECTED]> To: <vortex-l@eskimo.com> Sent: Wednesday, February 14, 2007 7:27 AM Subject: Re: [Vo]: Voltage versus field, and the electrophorus > In a 2 plate capacitor when together the field strength is concentrated more > on the inside of the 2 plates, while there is the same net field once > separated now it is spread out, and the field of the opposite plate isn't in > range so actually it is a lot weaker. > > > On 2/14/07, Robin van Spaandonk <[EMAIL PROTECTED]> wrote: >> >> In reply to John Berry's message of Fri, 9 Feb 2007 08:12:00 +1300: >> Hi, >> [snip] >> >That's how many electrostatic machines work such as the Wimshurst. >> > >> >There are 3 different things, voltage, field strength and charge >> imbalance, >> >in this case the Voltage goes up, however the field strength goes down >> >(though is still considerable and covers more area) and the charge >> imbalance >> >obviously remains the same. >> > >> >It is also possible to increase the electric field density without >> changing >> >the voltage or net charge imbalance by use of a point. >> [snip] >> If the charge remains constant while the plates are being pulled apart, >> and the >> capacitance if inversely proportional to the separation distance, then the >> voltage should be proportional to the separation distance, and >> consequently the >> field strength (Voltage / distance) should be constant. >> >> However it's afternoon, and I may I have goofed once again. :( >> >> Regards, >> >> Robin van Spaandonk >> >> http://users.bigpond.net.au/rvanspaa/ >> >> Competition provides the motivation, >> Cooperation provides the means. >> >> >
