A series RLC circuit consisting of R = 10 ohms, XL = 20

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A series RLC circuit consisting of R = 10 ohms, X_L = 20 ohms and X_c = 20 ohms is connected across an ac supply of 100 V (rms). The magnitude and phase angle (with reference to supply voltage) of the voltage across the inductive coil are respectively

1. 100 V, 90°
2. 100 V, – 90°
3. 200 V, – 90°
4. 200 V, 90°

Correct Option: D

Since reactance are cancelling each other, the circuit is purely resistive and the current is in phase with the applied voltage. The voltage across the inductor leads the current through it by 90° .
Since I = 100 ∠0° / {10 + j (20 – 20) } = 10∠0° V_L = jLωI = 20 × 10 ∠90 = 200 ∠90°