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Re: [Phys-l] [Electric potential of charged spheres







________________________________

From: John Denker <jsd@av8n.com>
To: Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
Sent: Thursday, 1 December 2011 2:00 AM
Subject: Re: [Phys-l] [Electric potential of charged spheres

work is done by repulsion when we separate them. These are not
equal due to different charge distributions. Should we not take this
into account?

regards,
Sarma..



On 11/29/2011 03:08 PM, Paul Nord wrote:
Well, John argued that the total capacitance of the two spheres in
contact (or near each other) would be less than the sum of the two
spheres individually.  I presumed that it might actually be greater
because the two-sphere system "looks like" a much larger single
sphere (to a very rough approximation).  If John is correct, the
voltage is between 5V and 10V.  If I'm correct, the voltage is less
than 5V.

OK.

1) Start with the original situation, v=1V and v=9V, spheres far apart.

2) Bring them together long enough to symmetrize the charge, then
move them back to their original positions.  v=5V and v=5V now.

Work is done against repulsion when we bring them together and