Question

Question 14 Mica capacitors are commonly used, high-precision capacitors in which the gap between the metal plates is filled with the dielectric material, mica. Considera typical 100 pF mica capacitor (1pF 10-12F). Assuming that the dielectric strength of the material is 118MV- 1.18 x 108 V, and that the thickness of the mica in the capacitor is 25.7 μm thick φ1m-10-6m). (The dielectric strength is the maximum electric field that the material can withstand without breaking down.) Calculate the maximum allowed voltage for this capacitor before dielectric breakdown occurs. (Assume that the electric field inside the capacitor can be approximated as being uniform.)

Answer 1

Given E = 1.18 times 10^8 v/m thickness d = 25.7 m d = 25.7 times 10^-6 m. V = E d = 1.18 times 10^8 V/m (25.7 times 10^-6 m) V = 3.03 times 10^3 V