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MHT CET 2024 (3 May, Shift 2) · RL and RC Series Circuits

RL and RC Series Circuits question from MHT CET 2024 (3 May, Shift 2)

Q29MHT CET 2024 · 3 MAY · SHIFT 2Medium

RL and RC Series Circuits

When 80 volt d.c. is applied across a solenoid, a current of 0.8 A flows in it. When 80 volt a.c. is applied across the same solenoid, the current becomes 0.4 A. If the frequency of a.c. source is 50 Hz, the impedance and inductance of the solenoid is nearly

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Answer: (a)

  1. DC: R=800.8=100 ΩR = \frac{80}{0.8} = 100\ \Omega. AC: Z=800.4=200 ΩZ = \frac{80}{0.4} = 200\ \Omega.
  2. XL=2002−1002=1003≈173 ΩX_L = \sqrt{200^2 - 100^2} = 100\sqrt{3} \approx 173\ \Omega
  3. L=1732π×50=173314≈0.55 HL = \frac{173}{2\pi \times 50} = \frac{173}{314} \approx 0.55\text{ H}
  4. So the answer is (a) 200 Ω200\ \Omega, 0.55 H.
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