# Does distance inbetween the plates of a capacitor have an effect on its charge?

1. Oct 27, 2012

### letsgo

You have a parallel plate capacitor, each with opposite charge Q, connected to a battery of some voltage.

What I'm wondering, is does the distance inbetween these plates have an effect on their charge, while connected to the battery? What about if the distance was changed after being disconnected from the battery?

What I think, is if the distance was doubled (while connected to the battery) the V=Ed would double, the C=(elipson)(A)/d would half, therefore the Q=CV would stay the same.

And if the distance was doubled after disconnected from the battery, V stays fixed, so does C, and therefore Q does as well.

Are those assumptions correct?

2. Oct 27, 2012

### DrZoidberg

It's the other way around. If the battery stays connected V stays the same and therefore the charge changes. If you disconnect the battery the charge stays the same since there is no way for the charge to flow away. So V changes.