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 V60 HzR = 50 ΩL = 50 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 = 50 mH
|Z| = Ω
2.Easy
120 V50 HzR = 60 ΩC = 100 µF

A series RC circuit is connected to a 120 V (rms), 50 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 120 V (rms)f = 50 HzR = 60 ΩC = 100 µF
φ = °
3.Medium
100 V60 HzR = 15 ΩC = 47 µFI

A resistor and a capacitor are connected in parallel across a 100 V (rms), 60 Hz supply. Find the rms current I.

V = 100 V (rms)f = 60 HzR = 15 ΩC = 47 µF
I = A
4.Medium
230 V500 HzR = 80 ΩL = 200 mHC = 10 µF

A series RLC circuit is connected to a 230 V (rms), 500 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 230 V (rms)f = 500 HzR = 80 ΩL = 200 mHC = 10 µF
φ = °
5.Hard
12 V100 HzR = 15 ΩL = 250 mHC = 100 µFI

A series RLC circuit is connected to a 12 V (rms), 100 Hz supply. Find the rms current I.

V = 12 V (rms)f = 100 HzR = 15 ΩL = 250 mHC = 100 µF
I = A
6.Hard
10 V100 HzR = 50 ΩL = 20 mHC = 10 µF

A series RLC circuit is connected to a 10 V (rms), 100 Hz supply. Find the resonant frequency f0 of the circuit.

V = 10 V (rms)f = 100 HzR = 50 ΩL = 20 mHC = 10 µF
f0 = Hz

Answer key

  1. 1. |Z| = 53.44 Ω
  2. 2. φ = −27.95 °
  3. 3. I = 6.898 A
  4. 4. φ = 82.36 °
  5. 5. I = 0.08453 A
  6. 6. f0 = 355.9 Hz

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