Question

Two parallel plate capacitors have circular plates. The magnitude of the charge on these plates is the same. However, the electric field between the plates of the first capacitor is 2.2e5 N/C, while the field within the second capacitor is 3.8e5 N/C. Determine the ratio r_2/r_1 for the plate radius for the second capacitor to the plate radius for the first capacitor.
6.5e-2 N/C
7.6e-2 N/C
7.6e-1 N/C
0.8e-1 N/C

Answer 1

Use the field to solve for charge density...you have a formula for that on a circular plate.