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
V500 HzL = 2.2 mH

Find the reactance XL of a 2.2 mH inductor at 500 Hz.

L = 2.2 mHf = 500 Hz
XL = Ω
2.Easy
120 V50 HzR = 15 ΩL = 20 mH

A series RL circuit is connected to a 120 V (rms), 50 Hz supply. Find the magnitude of the impedance |Z|.

V = 120 V (rms)f = 50 HzR = 15 ΩL = 20 mH
|Z| = Ω
3.Medium
230 V50 HzR = 80 ΩL = 250 mHC = 10 µF

A series RLC circuit is connected to a 230 V (rms), 50 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 230 V (rms)f = 50 HzR = 80 ΩL = 250 mHC = 10 µF
φ = °
4.Medium
230 V100 HzR = 50 ΩL = 250 mHC = 100 µFI

A series RLC circuit is connected to a 230 V (rms), 100 Hz supply. Find the rms current I.

V = 230 V (rms)f = 100 HzR = 50 ΩL = 250 mHC = 100 µF
I = A
5.Hard
10 V100 HzR = 15 ΩL = 150 mHC = 47 µF

A series RLC circuit is connected to a 10 V (rms), 100 Hz supply. Find the resonant frequency f0 of the circuit.

V = 10 V (rms)f = 100 HzR = 15 ΩL = 150 mHC = 47 µF
f0 = Hz
6.Hard
12 Vf0​R = 2 ΩL = 20 mHC = 4.7 µF

A series RLC circuit is driven by a 12 V (rms) source whose frequency is set to the resonant frequency of the circuit. Find the rms voltage VL across the inductor.

V = 12 V (rms)R = 2 ΩL = 20 mHC = 4.7 µF
VL = V

Answer key

  1. 1. XL = 6.912 Ω
  2. 2. |Z| = 16.26 Ω
  3. 3. φ = −71.55 °
  4. 4. I = 1.536 A
  5. 5. f0 = 59.94 Hz
  6. 6. VL = 391.4 V

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