AC impedance & phasors worksheet with answers

Free printable AC impedance & phasors worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
120 V60 HzR = 80 ΩC = 10 µF

A series RC circuit is connected to a 120 V (rms), 60 Hz supply. Find the magnitude of the impedance |Z|.

V = 120 V (rms)f = 60 HzR = 80 ΩC = 10 µF
|Z| = Ω
2.Easy
50 V60 HzR = 30 ΩL = 250 mH

A series RL circuit is connected to a 50 V (rms), 60 Hz supply. Find the magnitude of the impedance |Z|.

V = 50 V (rms)f = 60 HzR = 30 ΩL = 250 mH
|Z| = Ω
3.Medium
230 V200 HzR = 100 ΩL = 20 mHC = 47 µF

A series RLC circuit is connected to a 230 V (rms), 200 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 230 V (rms)f = 200 HzR = 100 ΩL = 20 mHC = 47 µF
φ = °
4.Medium
120 V50 HzR = 10 ΩL = 200 mHC = 100 µFI

A series RLC circuit is connected to a 120 V (rms), 50 Hz supply. Find the power factor cos φ of the circuit.

V = 120 V (rms)f = 50 HzR = 10 ΩL = 200 mHC = 100 µF
cos φ =
5.Hard
12 V50 HzR = 20 ΩL = 200 mHC = 47 µF

A series RLC circuit is connected to a 12 V (rms), 50 Hz supply. Find the resonant frequency f0 of the circuit.

V = 12 V (rms)f = 50 HzR = 20 ΩL = 200 mHC = 47 µF
f0 = Hz
6.Hard
24 V100 HzR = 60 ΩL = 150 mHC = 22 µF

A series RLC circuit is connected to a 24 V (rms), 100 Hz supply. Find the resonant frequency f0 of the circuit.

V = 24 V (rms)f = 100 HzR = 60 ΩL = 150 mHC = 22 µF
f0 = Hz

Answer key

  1. 1. |Z| = 277.1 Ω
  2. 2. |Z| = 98.91 Ω
  3. 3. φ = 4.689 °
  4. 4. cos φ = 0.307
  5. 5. f0 = 51.91 Hz
  6. 6. f0 = 87.61 Hz

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