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
100 V60 HzR = 100 ΩL = 100 mHI

A series RL circuit is connected to a 100 V (rms), 60 Hz supply. Find the rms current I.

V = 100 V (rms)f = 60 HzR = 100 ΩL = 100 mH
I = A
2.Easy
100 V50 HzR = 100 ΩL = 250 mH

A series RL circuit is connected to a 100 V (rms), 50 Hz supply. Find the rms voltage VL across the inductor.

V = 100 V (rms)f = 50 HzR = 100 ΩL = 250 mH
VL = V
3.Medium
120 V100 HzR = 60 ΩC = 10 µFI

A resistor and a capacitor are connected in parallel across a 120 V (rms), 100 Hz supply. Find the magnitude of the impedance |Z|.

V = 120 V (rms)f = 100 HzR = 60 ΩC = 10 µF
|Z| = Ω
4.Medium
50 V200 HzR = 60 ΩL = 200 mHC = 1 µF

A series RLC circuit is connected to a 50 V (rms), 200 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 50 V (rms)f = 200 HzR = 60 ΩL = 200 mHC = 1 µF
φ = °
5.Hard
50 V500 HzR = 10 ΩL = 50 mHC = 47 µFI

A series RLC circuit is connected to a 50 V (rms), 500 Hz supply. Find the rms current I.

V = 50 V (rms)f = 500 HzR = 10 ΩL = 50 mHC = 47 µF
I = A
6.Hard
230 V100 HzR1​ = 10 ΩR2​ = 20 ΩC = 22 µFI

A resistor R1 is connected in series with a parallel combination of R2 and a capacitor C, across a 230 V (rms), 100 Hz supply. Find the rms current I.

V = 230 V (rms)f = 100 HzR1 = 10 ΩR2 = 20 ΩC = 22 µF
I = A

Answer key

  1. 1. I = 0.9357 A
  2. 2. VL = 61.77 V
  3. 3. |Z| = 56.14 Ω
  4. 4. φ = −83.71 °
  5. 5. I = 0.3319 A
  6. 6. I = 7.921 A

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