Question

An AC power supply is connected in series with a light bulb, a capacitor, and an ammeter.

a) Would the ammeter measure a current? Please explain.

b) Can charges flow through the capacitor, i.e. go from on plate to the other plate through the dielectric? Please explain.  

Answer 1

(a) Yes, When AC current flows through the circuit, the bulb glows. Capacitor allows the passage of AC current, however it blocks DC volatge.

(b) Capacitor offers capacitive reactance. It offers opposion to current flow. For high frequency input, it opposes less and vice versa.  Before switch is closed, there is no voltages across capacitor. In this case, capacitor uncharged. After switch is closed, it has ability to shift the phase of current. In this case, there exist a momentarlily surge of electrons between the plates.