Q: An alternating voltage E = 200√2 sin (100t) volt is connected to a 1μF capacitor through an ac ammeter. What will be the reading of the ammeter ?

Sol: Comparing E = 200√2 sin (100 t) with

E = E_{0} sin ωt ; E_{0} = 200 √2 V and ω = 100 rad/s

$\large X_C = \frac{1}{\omega C} = \frac{1}{100 \times 10^{-6}} $

= 10^{4} Ω

$\large i_{rms} = \frac{E_{rms}}{X_C} = \frac{E_0}{\sqrt{2} X_C} $

$\large = \frac{200 \sqrt{2} }{\sqrt{2} \times 10^4} $

= 20 mA