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
24 V60 HzR = 60 ΩL = 150 mHI

A series RL circuit is connected to a 24 V (rms), 60 Hz supply. Find the rms current I.

V = 24 V (rms)f = 60 HzR = 60 ΩL = 150 mH
I = A
2.Easy
120 V50 HzR = 30 ΩL = 50 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 = 30 ΩL = 50 mH
|Z| = Ω
3.Medium
12 V1000 HzR = 100 ΩL = 200 mHC = 1 µFI

A series RLC circuit is connected to a 12 V (rms), 1000 Hz supply. Find the rms current I.

V = 12 V (rms)f = 1000 HzR = 100 ΩL = 200 mHC = 1 µF
I = A
4.Medium
230 V500 HzR = 20 ΩL = 100 mHC = 100 µFI

A series RLC circuit is connected to a 230 V (rms), 500 Hz supply. Find the rms current I.

V = 230 V (rms)f = 500 HzR = 20 ΩL = 100 mHC = 100 µF
I = A
5.Hard
5 Vf0​R = 5 ΩL = 50 mHC = 2.2 µF

A series RLC circuit is driven by a 5 V (rms) source whose frequency is set to the resonant frequency of the circuit. Find the rms voltage VL across the inductor.

V = 5 V (rms)R = 5 ΩL = 50 mHC = 2.2 µF
VL = V
6.Hard
VfR = 10 ΩL = 5 mHC = 0.01 µF

A series RLC circuit has R = 10 Ω, L = 5 mH and C = 0.01 µF. Find its quality factor Q at resonance.

R = 10 ΩL = 5 mHC = 0.01 µF
Q =

Answer key

  1. 1. I = 0.2911 A
  2. 2. |Z| = 33.86 Ω
  3. 3. I = 0.01089 A
  4. 4. I = 0.7381 A
  5. 5. VL = 150.8 V
  6. 6. Q = 70.71

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