Question

In a parallel plate capacitor with air between the plates, each plate has an area of $6\times {10}^{-3}{m}^2$ and the distance between the plates is 3mm. Calculate the capacitance of the capacitor. If this capacitor is connected to a 100 V supply, what is the charge on each plate of the capacitor?

Answer 1

Area of each plate $A=6\times {10}^{-3}{m}^2$

Distance between the plates $d=3mm=0.003m$

Capacitance of capacitor $C=\frac{A{ϵ}_o}{d}$

$\therefore$ $C=\frac{6\times {10}^{-3}\times 8.85\times {10}^{-12}}{0.003}=17.7pF$

Voltage across the capacitor $V=100$ volts

Thus charge on each plate $Q=CV$

$\therefore$ $Q=17.7\times {10}^{-12}\times 100$

$⟹$ $Q=1.77\times {10}^{-9}$ C