7.19 Suppose the circuit in Exercise 7.18 has a resistance of 15 . Obtain the average power transferred to each element of the circuit, and the total power absorbed.

 

Here,

Inductance, 𝐿 = 80 mH

Capacitance, 𝐶 = 60 μF

rms voltage 𝑉 = 230 V

Frequency, 𝑓 = 50 Hz

ω=2πf=2π×50Hz=100πrads1

Resistance, 𝑅𝑅 = 15 Ω

The impedance of the circuit –

Z=(XLXC)2+R2=(100π×80×1031100π×60×106)2+152=31.728Ω

Current following in the circuit-

Irms=VZ=230V31.72Ω=7.25A

The average power transferred to the resistor,

PR=Irms2R=7.252×15=791W

The average power transferred to the resistor and capacitor, PC=PI=0

As the average power transferred to the inductor and the capacitor is zero in one
complete cycle. Hence, the total transferred is 791 W.