Question

What is the power factor of an LCR series circuit at resonance?

Answer 1

Power factor,

cos Φ = \(\frac{R}{\sqrt{R^2+(\omega L-\frac{1}{\omega C}})^2}\)

In series resonance condition,

ωL = \(\frac{1}{\omega C}\) 

cos Φ = \(\frac{R}{R}\) = 1