Question

The power factor of a series LCR circuit when at resonance is :

• A. zero
• B. 0.5
• C. 1.0
• D. Depends on values of L, C and R

Answer 1

Answer: (C)

Power factor $\cos \varphi =\frac{R}{Z}$ Where Z= Impedance of the circuit at resonance, $Z=R$ $\therefore$ $\cos \varphi =1$