Circuits

What is the approximate magnitude of the impedance of a parallel R-L-C circuit at resonance?

Answer

Approximately equal to the circuit resistance.

At resonance the reactances cancel; a parallel R-L-C circuit shows a high impedance that is essentially just its resistance.

Source: FCC Element 3 question pool, 3D

Not the answer

  • Low, as compared to the circuit resistance.
  • Approximately equal to XC.
  • Approximately equal to XL.

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