Finding the E in the mica

1. Oct 11, 2005

mr_coffee

A parallel-plate capacitor has a capacitance of 60 pF, a plate area of 130 cm2, and a mica dielectric ( = 5.4). At 60 V potential difference, calculate the following values.

(a) E in the mica
wrong check mark V/m

(b) the magnitude of the free charge on the plates
C
(c) the magnitude of the induced surface charge on the mica
C

I tried the following:
E = [Q/A]/(k*Eo);
E = (1e-12/.013)/(5.4)(8.85e-12);
E = 1.609 which is wrong.

I got Q by the following: C = QV; Q = C/V; 60e-12/60 = 1e-12

2. Oct 17, 2005

Tom Mattson

Staff Emeritus
Sorry for the late reply. If you're still working on this then check out the websites I gave you in this thread and see if you don't have better luck.