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 V100 HzR = 10 ΩL = 20 mH

A series RL circuit is connected to a 120 V (rms), 100 Hz supply. Find the rms voltage VL across the inductor.

V = 120 V (rms)f = 100 HzR = 10 ΩL = 20 mH
VL = V
2.Easy
100 V60 HzR = 20 ΩL = 50 mHI

A series RL circuit is connected to a 100 V (rms), 60 Hz supply. Find the rms current I.

V = 100 V (rms)f = 60 HzR = 20 ΩL = 50 mH
I = A
3.Medium
50 V60 HzR = 15 ΩL = 150 mHC = 100 µF

A series RLC circuit is connected to a 50 V (rms), 60 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 50 V (rms)f = 60 HzR = 15 ΩL = 150 mHC = 100 µF
φ = °
4.Medium
12 V100 HzR = 40 ΩL = 100 mHC = 2.2 µF

A series RLC circuit is connected to a 12 V (rms), 100 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 12 V (rms)f = 100 HzR = 40 ΩL = 100 mHC = 2.2 µF
φ = °
5.Hard
10 V500 HzR = 40 ΩL = 250 mHC = 10 µF

A series RLC circuit is connected to a 10 V (rms), 500 Hz supply. Find the resonant frequency f0 of the circuit.

V = 10 V (rms)f = 500 HzR = 40 ΩL = 250 mHC = 10 µF
f0 = Hz
6.Hard
12 V50 HzR = 100 ΩL = 250 mHC = 47 µF+−VC​

A series RLC circuit is connected to a 12 V (rms), 50 Hz supply. Find the rms voltage VC across the capacitor.

V = 12 V (rms)f = 50 HzR = 100 ΩL = 250 mHC = 47 µF
VC = V

Answer key

  1. 1. VL = 93.9 V
  2. 2. I = 3.639 A
  3. 3. φ = 63.45 °
  4. 4. φ = −86.53 °
  5. 5. f0 = 100.7 Hz
  6. 6. VC = 8.08 V

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