- #1

waley

## Homework Statement

With just about any problem asking for "rate at which source is delivering electrical energy to the circuit" or "find the power of the circuit" in a LRC circuit, I get that you have to calculate for the average power. But the multiple equations confuse me - sometimes in problems like I mentioned above, you'd use P=0.5IVcosφ and sometimes you do without the cosφ term. If the circuit were at resonance, or in other words the power factor was raised to unity, then I see how cosφ disappears, but when you're talking about the entire circuit will all L, R, C components, not at resonance, why is it that I sometimes see people doing the problem without the cosφ?