Parallel Plate Capacitor

whoknows12345

Consider a parallel-plate capacitor constructed from two circular metal plates of radius R. The plates are seperated by a distance f 2.2 mm. What radius must the plates have if the capacitance of this capacitor is to be 2.2microF


I used the equation C=EA/d

2.2 x 10^-6 = (8.85x10^-6)(pie r^2)/(2.2 x 10^-3)
solve for r and I got .01319 m but it's not correct, what am I doing wrong?

whoknows12345

nevermind, i plugged it in wrong. i did it right.