Final answer:
The true power in a reactive A/C circuit is always less than the apparent power due to the phase angle between the source voltage and the current. At resonance or in a purely resistive circuit, the power factor is 1 and the average power is the highest.
Step-by-step explanation:
The true power in a reactive A/C circuit is always less than the apparent power.
In an AC circuit, there is a phase angle between the source voltage and the current. The average power delivered to an RLC circuit is affected by this phase angle and is given by Pave = Irms x Vrms x cosφ, where cosφ is called the power factor.
At resonance or in a purely resistive circuit, the power factor is 1 and the current and voltage are in phase. At other frequencies, the power factor is less than 1 and the average power is less than at resonance.