In a series RLC circuit, the frequency is 60 Hz and the source voltage measured using an AC voltmeter is 80 volts. The resistance is 80 ohms, the inductance is 0.15 H, and the capacitance is 24 microfarads.

a) Find the reactances and the impedance

b) Find the phase angle and the power factor

c) Find the maximum voltage supplied by the source

d) Find the maximum voltage drop across each component and show that the net is the same as part c.

e) Find the resonance frequency

Solution:

a) Reactances and Impedance

b) Since the net reactance is capacitive, the phase angle is in the fourth quadrant (negative). The power factor (P.F.) is the cosine of the phase angle.

c and d) The source voltage is an rms voltage, since it is measured using a voltmeter:

The net voltage has to be obtained using the Pythagorean rule:

e) To find the resonance frequency, we equate the formulas for the inductive and capacitive reactances, getting the equation