Question

An air-filled parallel-plate capacitor is to be constructed which can store 12 µC of charge when operated at 1200 V. What can be the minimum plate area of the capacitor? The dielectric strength of air is 3×106 V m-1.

Answer 1

The minimum plate area of the capacitor is 0.45 $m^2$

Explanation:

Given, Charge stored in capacitor (Q)= 12 µC

Operated Voltage (V) = 1200 V

The dielectric strength of air = 3×$10^{6}$ V m-1

V/d = 3 X $10^{-6}$ V/m

d=V/(V/d) = 4 X $10^{-4}$ m

We know c = Q/V = 12 X $10^{-8}$ /1200 = $10^{-8}$

Therefore C = ∈A/d = $10^{-8}$

From the above equation A= $10^{-8}$ X d/∈ = $10^{-8}$ X 4 X $10^{-4}$ /8.854 X $10^{-4}$

By solving the above values we can get , A = 0.45 $m^2$