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
10 V60 HzR = 60 ΩL = 250 mH

A series RL circuit is connected to a 10 V (rms), 60 Hz supply. Find the magnitude of the impedance |Z|.

V = 10 V (rms)f = 60 HzR = 60 ΩL = 250 mH
|Z| = Ω
2.Easy
12 V200 HzR = 15 ΩL = 20 mH

A series RL circuit is connected to a 12 V (rms), 200 Hz supply. Find the rms voltage VL across the inductor.

V = 12 V (rms)f = 200 HzR = 15 ΩL = 20 mH
VL = V
3.Medium
10 V500 HzR = 80 ΩL = 200 mHC = 1 µF

A series RLC circuit is connected to a 10 V (rms), 500 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 10 V (rms)f = 500 HzR = 80 ΩL = 200 mHC = 1 µF
φ = °
4.Medium
12 V100 HzR = 20 ΩL = 100 mHI

A resistor and an inductor are connected in parallel across a 12 V (rms), 100 Hz supply. Find the rms current I.

V = 12 V (rms)f = 100 HzR = 20 ΩL = 100 mH
I = A
5.Hard
12 V200 HzR = 100 ΩL = 150 mHC = 22 µFI

A series RLC circuit is connected to a 12 V (rms), 200 Hz supply. Find the rms current I.

V = 12 V (rms)f = 200 HzR = 100 ΩL = 150 mHC = 22 µF
I = A
6.Hard
10 Vf0​R = 15 ΩL = 50 mHC = 10 µF

A series RLC circuit is driven by a 10 V (rms) source whose frequency is set to the resonant frequency of the circuit. Find the rms voltage VL across the inductor.

V = 10 V (rms)R = 15 ΩL = 50 mHC = 10 µF
VL = V

Answer key

  1. 1. |Z| = 111.7 Ω
  2. 2. VL = 10.3 V
  3. 3. φ = 75.53 °
  4. 4. I = 0.6297 A
  5. 5. I = 0.06586 A
  6. 6. VL = 47.14 V

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