# Capacitor Question

#### notaphysicsmajor

How is the potential difference across a fully charged capacitor related to the capacitance?

#### oz93666

It's not ... and it doesn't matter if it's 'fully charged' or not ...

Potential difference is just voltage ... the voltage across a capacitor is it's voltage and unrelated to anything else.

#### studiot

You have the following relationships available based on the basic one

Q = CV Where Q is the charge on the capacitor, C is the capacitance and V is the votlage across it.

This can be translated to energy, E (Joules) as follows

$$\displaystyle E = \frac{1}{2}C{V^2} = \frac{1}{2}QV = \frac{1}{2}\frac{{{Q^2}}}{C}$$

Does this help?

#### notaphysicsmajor

You have the following relationships available based on the basic one

Q = CV Where Q is the charge on the capacitor, C is the capacitance and V is the votlage across it.

This can be translated to energy, E (Joules) as follows

$$\displaystyle E = \frac{1}{2}C{V^2} = \frac{1}{2}QV = \frac{1}{2}\frac{{{Q^2}}}{C}$$

Does this help?
awesome thank you!