What average power is delivered to the circuit by the source?

An LRC series circuit is connected to a 120Hz ac source that has V(rms)=80V. the circuit has a resistance of 75ohm and impedance at this frequency of 105ohm. What average power is delivered to the circuit by the source?|||Since the impedance is 105 Ohms, and the RMS voltage is 80v, the RMS current is 80/105 = 0.762A



The average power is then R*I^2 = 75*0.762^2 = 43.5W



Just in case there is any misunderstanding, in those parts of the world where the electricity supply is said to be 120v, this is an RMS value.



The other thing I have noticed about this question is that if the '120v ac source' is supposed to be sinusoidal with a peak value of 120v, then the RMS value would be 120/sqrt(2) = 84.85V, not 80v. So I suppose that this is not a sinusoidal supply. This makes my answer approximate, since the concept of impedance is only applicable to a sinusoidal waveform, or to a single frequency; a non-sinusoidal waveform will contain several different frequency components. You had better check that the 80v is correct, or discuss this with your teacher.