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
230 V60 HzR = 25 ΩL = 150 mH

A series RL circuit is connected to a 230 V (rms), 60 Hz supply. Find the magnitude of the impedance |Z|.

V = 230 V (rms)f = 60 HzR = 25 ΩL = 150 mH
|Z| = Ω
2.Easy
50 V60 HzR = 15 ΩL = 50 mHI

A series RL circuit is connected to a 50 V (rms), 60 Hz supply. Find the rms current I.

V = 50 V (rms)f = 60 HzR = 15 ΩL = 50 mH
I = A
3.Medium
24 V60 HzR = 80 ΩL = 250 mHC = 47 µF

A series RLC circuit is connected to a 24 V (rms), 60 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 24 V (rms)f = 60 HzR = 80 ΩL = 250 mHC = 47 µF
φ = °
4.Medium
Vf0​ = 1000 HzRL = 20 mHC = ?

A series RLC circuit with L = 20 mH must resonate at 1000 Hz. Find the capacitance C needed.

f0 = 1000 HzL = 20 mH
C = µF
5.Hard
100 V1000 HzR = 60 ΩL = 50 mHC = 1 µFI

A series RLC circuit is connected to a 100 V (rms), 1000 Hz supply. Find the rms current I.

V = 100 V (rms)f = 1000 HzR = 60 ΩL = 50 mHC = 1 µF
I = A
6.Hard
100 V200 HzR = 100 ΩL = 20 mHC = 2.2 µF+−VC​

A series RLC circuit is connected to a 100 V (rms), 200 Hz supply. Find the rms voltage VC across the capacitor.

V = 100 V (rms)f = 200 HzR = 100 ΩL = 20 mHC = 2.2 µF
VC = V

Answer key

  1. 1. |Z| = 61.83 Ω
  2. 2. I = 2.076 A
  3. 3. φ = 25.3 °
  4. 4. C = 1.267 µF
  5. 5. I = 0.6016 A
  6. 6. VC = 103 V

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