Q. 295.0( 1 Vote )

An ac voltage v = vm sinωt is applied to a series LCR circuit. Obtain the expression for current in the circuit and the phase angle between current and voltage. What is the resonance frequency?


An ac voltage v = vm sinωt is applied to a pure inductor L. Obtain an expression for the current in the circuit. Prove that the average power supplied to an inductor over one complete cycle is zero.

Answer :

Current through resister, Vr=IR

Current through inductor, VL=IL

Current through inductor, VL=

Now, impedance resistance is,

So, current, I=

The resonance frequency is the frequency in which Z=R, means XC=XL,

Or, L=



Or, This is the value of resonance frequency in LCR Circuit.


(As, self induced voltage = applied voltage)

We know that, or


Now, average of is 0.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.