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
Vf = ?L = 5 mH

At what frequency f does a 5 mH inductor have a reactance of 50 Ω?

L = 5 mHXL = 50 Ω
f = Hz
2.Easy
50 V60 HzR = 30 ΩL = 250 mH

A series RL circuit is connected to a 50 V (rms), 60 Hz supply. Find the rms voltage VR across the resistor.

V = 50 V (rms)f = 60 HzR = 30 ΩL = 250 mH
VR = V
3.Medium
230 V60 HzR = 20 ΩL = 20 mHI

A resistor and an inductor are connected in parallel across a 230 V (rms), 60 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 230 V (rms)f = 60 HzR = 20 ΩL = 20 mH
φ = °
4.Medium
12 V60 HzR = 30 ΩL = 50 mHI

A resistor and an inductor are connected in parallel across a 12 V (rms), 60 Hz supply. Find the magnitude of the impedance |Z|.

V = 12 V (rms)f = 60 HzR = 30 ΩL = 50 mH
|Z| = Ω
5.Hard
24 V1000 HzR = 50 ΩL = 50 mHC = 10 µFI

A series RLC circuit is connected to a 24 V (rms), 1000 Hz supply. Find the rms current I.

V = 24 V (rms)f = 1000 HzR = 50 ΩL = 50 mHC = 10 µF
I = A
6.Hard
50 V60 HzR = 60 ΩL = 20 mHC = 47 µF+−VC​

A series RLC circuit is connected to a 50 V (rms), 60 Hz supply. Find the rms voltage VC across the capacitor.

V = 50 V (rms)f = 60 HzR = 60 ΩL = 20 mHC = 47 µF
VC = V

Answer key

  1. 1. f = 1592 Hz
  2. 2. VR = 15.17 V
  3. 3. φ = 69.34 °
  4. 4. |Z| = 15.96 Ω
  5. 5. I = 0.07936 A
  6. 6. VC = 36.46 V

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