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 = 30 ΩL = 150 mHI

A series RL circuit is connected to a 120 V (rms), 60 Hz supply. Find the rms current I.

V = 120 V (rms)f = 60 HzR = 30 ΩL = 150 mH
I = A
2.Easy
230 V200 HzR = 15 ΩC = 22 µF

A series RC circuit is connected to a 230 V (rms), 200 Hz supply. Find the magnitude of the impedance |Z|.

V = 230 V (rms)f = 200 HzR = 15 ΩC = 22 µF
|Z| = Ω
3.Medium
100 V500 HzR = 10 ΩL = 50 mHC = 4.7 µFI

A series RLC circuit is connected to a 100 V (rms), 500 Hz supply. Find the power factor cos φ of the circuit.

V = 100 V (rms)f = 500 HzR = 10 ΩL = 50 mHC = 4.7 µF
cos φ =
4.Medium
10 V1000 HzR = 80 ΩL = 100 mHC = 100 µFI

A series RLC circuit is connected to a 10 V (rms), 1000 Hz supply. Find the rms current I.

V = 10 V (rms)f = 1000 HzR = 80 ΩL = 100 mHC = 100 µF
I = A
5.Hard
24 Vf0​R = 2 ΩL = 5 mHC = 0.47 µF

A series RLC circuit is driven by a 24 V (rms) source whose frequency is set to the resonant frequency of the circuit. Find the rms voltage VL across the inductor.

V = 24 V (rms)R = 2 ΩL = 5 mHC = 0.47 µF
VL = V
6.Hard
2 Vf0​R = 5 ΩL = 20 mHC = 0.47 µF

A series RLC circuit is driven by a 2 V (rms) source whose frequency is set to the resonant frequency of the circuit. Find the rms voltage VL across the inductor.

V = 2 V (rms)R = 5 ΩL = 20 mHC = 0.47 µF
VL = V

Answer key

  1. 1. I = 1.875 A
  2. 2. |Z| = 39.16 Ω
  3. 3. cos φ = 0.1112
  4. 4. I = 0.01583 A
  5. 5. VL = 1238 V
  6. 6. VL = 82.51 V

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