AC Voltage Applied To A Capacitor - Practice Questions & MCQ

AC voltage applied to a capacitor:

 The circuit containing alternating voltage source V=V₀sinωt connected to a capacitor of capacitance C.

Suppose at any time t, q be the charge on the capacitor and i be the current in the circuit. Since there is no resistance in the circuit, so the instantaneous potential drop across the capacitor must be equal to applied alternating voltage so,

Since   is the instantaneous current in the circuit so, 

Where,    is the peak value of current.

Comparing equation of current  with V=V₀sinωt ,we see that in a perfect capacitor current leads the emf by a phase angle of π/2.

Again comparing peak value of current with ohm's law ,we find that quantity 1/ωC has the dimension of the resistance. 

Thus the quantity  is known as capacitive reactance. 

Phase difference (between voltage and current):

Power :

P= 0 

Power factor :

Time difference:

T.D =