# I am having trouble with a Capacitor problem I can't find the find formula for.

1. Dec 3, 2012

### jjj0922

1. The problem statement, all variables and given/known data

The two metal plates of a capacitor are separated by a distance of 1mm. The electric field between the two plates is measured to be 100 N/C. If the capacitance is measured to be 5 uF, what is the magnitude of the charge on each plate, in Coulombs?

2. Relevant equations
That's my problem as I can't find the appropriate equation.

3. The attempt at a solution
Spent hours searching for the equation and now I'm too frustrated to continue.

2. Dec 3, 2012

### Staff: Mentor

Welcome to the PF.

Well, what equations do you have that are related to capacitance? I'm at home and my EE books are at work, but it seems that you don't know the area of the cap so you can't work with the Q=CV equation directly at first. Can you convert that electric field into V/m units instead? That would give you the cap voltage, and knowing the measured capacitance would give you the Q value....