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
50 V60 HzR = 30 ΩL = 50 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 = 50 mH
|Z| = Ω
2.Easy
12 V50 HzR = 10 ΩL = 200 mH

A series RL circuit is connected to a 12 V (rms), 50 Hz supply. Find the rms voltage VL across the inductor.

V = 12 V (rms)f = 50 HzR = 10 ΩL = 200 mH
VL = V
3.Medium
50 V50 HzR = 10 ΩL = 150 mHC = 22 µF

A series RLC circuit is connected to a 50 V (rms), 50 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 50 V (rms)f = 50 HzR = 10 ΩL = 150 mHC = 22 µF
φ = °
4.Medium
230 V60 HzR = 60 ΩL = 200 mHC = 10 µFI

A series RLC circuit is connected to a 230 V (rms), 60 Hz supply. Find the rms current I.

V = 230 V (rms)f = 60 HzR = 60 ΩL = 200 mHC = 10 µF
I = A
5.Hard
24 Vf0​R = 10 ΩL = 100 mHC = 10 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 = 10 ΩL = 100 mHC = 10 µF
VL = V
6.Hard
12 V100 HzR = 15 ΩL = 20 mHC = 47 µF

A series RLC circuit is connected to a 12 V (rms), 100 Hz supply. Find the resonant frequency f0 of the circuit.

V = 12 V (rms)f = 100 HzR = 15 ΩL = 20 mHC = 47 µF
f0 = Hz

Answer key

  1. 1. |Z| = 35.43 Ω
  2. 2. VL = 11.85 V
  3. 3. φ = −84.15 °
  4. 4. I = 1.155 A
  5. 5. VL = 240 V
  6. 6. f0 = 164.2 Hz

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