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 V50 HzR = 10 ΩL = 200 mH

A series RL circuit is connected to a 120 V (rms), 50 Hz supply. Find the rms voltage VR across the resistor.

V = 120 V (rms)f = 50 HzR = 10 ΩL = 200 mH
VR = V
2.Easy
120 V60 HzR = 50 ΩL = 20 mH

A series RL circuit is connected to a 120 V (rms), 60 Hz supply. Find the magnitude of the impedance |Z|.

V = 120 V (rms)f = 60 HzR = 50 ΩL = 20 mH
|Z| = Ω
3.Medium
120 V1000 HzR = 30 ΩL = 20 mHC = 10 µFI

A series RLC circuit is connected to a 120 V (rms), 1000 Hz supply. Find the rms current I.

V = 120 V (rms)f = 1000 HzR = 30 ΩL = 20 mHC = 10 µF
I = A
4.Medium
10 V1000 HzR = 100 ΩL = 200 mHC = 1 µF

A series RLC circuit is connected to a 10 V (rms), 1000 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 10 V (rms)f = 1000 HzR = 100 ΩL = 200 mHC = 1 µF
φ = °
5.Hard
VfR = 10 ΩL = 20 mHC = 0.47 µF

A series RLC circuit has R = 10 Ω, L = 20 mH and C = 0.47 µF. Find its bandwidth B (the width of the band between the half-power frequencies), in Hz.

R = 10 ΩL = 20 mHC = 0.47 µF
B = Hz
6.Hard
50 V1000 HzR = 80 ΩL = 150 mHC = 100 µFI

A series RLC circuit is connected to a 50 V (rms), 1000 Hz supply. Find the rms current I.

V = 50 V (rms)f = 1000 HzR = 80 ΩL = 150 mHC = 100 µF
I = A

Answer key

  1. 1. VR = 18.86 V
  2. 2. |Z| = 50.57 Ω
  3. 3. I = 1.055 A
  4. 4. φ = 84.79 °
  5. 5. B = 79.58 Hz
  6. 6. I = 0.05295 A

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