Which phasor diagram represents LCR circuit at resonance?

In a series LCR circuit, the voltage across the inductor (V_L$) leads the current (I$) by $90^{{}^{\circ}}$, while the voltage across the capacitor (V_C$) lags the current by 90^{{}^{\circ}}$. The voltage across the resistor (V_R$) is in phase with the current.<br><br>At resonance, the inductive reactance is equal to the capacitive reactance (X_L = X_C$). Consequently, the voltage across the inductor is equal in magnitude to the voltage across the capacitor (V_L = V_C$).<br><br>Since$V_L$and$V_C$are 180^{{}^{\circ}}$ out of phase and equal in magnitude, they cancel each other out completely. The net voltage $V$ across the circuit is simply the voltage across the resistor (V = V_R$).<br><br>Because the total voltage is purely resistive at resonance, it is in phase with the current$I$. This means the phase angle \phi$ between the total voltage and the current is $0^{{}^{\circ}}$.

Looking at the given options, Fig. (d) correctly shows the phase angle $\phi = 0^{{}^{\circ}}$ with the voltage $V_R$ in phase with the current $I$.

Answer: fig.(d)