Physics - EMI/AC Question with Solution | TestHub

At resonance $X_L=X_C$ or $\omega L=\frac{1}{\omega C}$. Because of this impedance of $LCR$ series circuit become equal to resistance of circuit $\left(Z=\sqrt{R^2+{\left(X_L-X_C\right)}^2}\right)$. Therefore from $I=\frac{E}{Z}=\frac{E}{R}$, at resonance, current in LCR series circuit is maximum. Correspondingly phase angle is also equal to zero. Therefore emf and current are in phase in $LCR$ series circuit.