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A series L C R circuit with 100  Ω resistance is connected to an ac source of 200 V with an angular frequency of 300 rad s - 1 . If only the capacitor is removed, the current lags behind the voltage by a phase of 60 ∘ . If only the inductor is removed, the current leads the voltage by a phase of 60 ∘ . The current and the power dissipated in the circuit is

Options

  1. A3 A , 300 W
  2. B5 A , 100 W
  3. C4 A , 200 W
  4. D2 A , 400 W

Correct answer

D. 2 A , 400 W

Step-by-step solution

From given condition circuit is at resonance For LR circuit, tan 60 = X L R ⇒ X L = 3 R For CR circuit tan 60 = X C R ⇒ X C = 3 R ⇒ X L = X C = 3 R I rms = V rms R = 200 100 = 2 Amp P = I 2 R = 4 × 100 = 400 Watt

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