1. The problem statement, all variables and given/known data A parallel plate capacitor is constructed with plates of area .0280 m^2 and separation .550mm Find the charge on each plate when potential difference between plates is 20.1V. what separation would be necessary to give a charge of 20 nC on each plate? 2. Relevant equations Im not sure that is where i am confused[/b] 3. The attempt at a solution I do not even know which equations to use.... I think it might be C=εA/d and another question is what is the difference between C=Q/V and C=εA/d??? When should i choose between using the two.? but I'm taking a shot in the dark.