Capacitance of concentric shells

[kenneth1100]

for the part of Capacitance of concentric shells

why Va equals that?


why the voltage on the surface of a is affected by -Q/(4pi*epsilon*b),
which represents the voltage on the surface of b

these two voltage represents something at different position!!

 

[LowlyPion]

Welcome to PF.

Perhaps you can explain a little more about what you are having trouble with?

In the mean time perhaps this link will be helpful?
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/gaulaw.html#c2

 

[kenneth1100]

thank you
i forgot that V in a shell/sphere is the same as if it's on the surface
I thought the p.d. by the larger shell were different on the surface of the larger shell and on the surface on the smaller shell........
that's why i got trouble

anyway, thanks~