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NEET 2020 (Phase 1) · Series LCR Circuit

Series LCR Circuit question from NEET 2020 (Phase 1)

Q55NEET 2020 · PHASE 1Medium

Series LCR Circuit

A series LCR circuit is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is π3\frac{\pi}{3}. If instead C is removed from the circuit, the phase difference is again π3\frac{\pi}{3} between current and voltage. The power factor of the circuit is:

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Answer: (b)

  1. L removed: XC=3RX_C = \sqrt{3}R; C removed: XL=3RX_L = \sqrt{3}R.
  2. XL=XC⇒X_L = X_C \Rightarrow resonance, Z=RZ = R.
  3. Power factor =RZ=1.0= \dfrac{R}{Z} = 1.0. So the answer is (b) 1.0.
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