# Charge distribution over two thin concentric spherical shells

## Homework Statement

"A thin conducting spherical shell of radius a carries a charge q. Concentric with this is another spherical shell of radius b>a carrying a net charge Q. Describe how the charge is distributed between the inner and outer surfaces of the shells. What is te capacitance of the two shells?"

## The Attempt at a Solution

Is it correct to say that there would be a charge +q on the outer surface of the inner shell. Due to induced charge there would then be a charge -q on the inner surface of the outer shell. Therefore there would be a charge +Q-q on the outer surface of the outer shell.

For the capacitance does it want the capacitance of the overall system. C=Q/V ???????

## Answers and Replies

Q is the net charge, when i did this question i took it to mean that Q=-q as it is induced by the +q on the inner sphere. note: to be a capacitor the two plates have to carry equal and opposite charges.

use gauss' law to get the field and then go from there in order to get the capacitance.

+Q-q ???