An air-filled parallel-plate capacitor is to have a capacitance of 0.4 F. If the distance between the plates is 0.7mm, calculate the required surface area of each plate. Answer in mi^2. Okay, so I used the Capacitance equation where C=(EoA)/d where Eo is a constant 8.85e-12 C^2/N.m^2 and A is the Area of the plates and d is the plate seperation. So I plugged in the numbers, found the area and divided it by two to get the area of each plate. I'm getting the wrong answer and I don't know what I'm doing wrong. If anyone could please help, it would be appreciated. Thank you.