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 = 25 ΩL = 20 mH

A series RL circuit is connected to a 120 V (rms), 50 Hz supply. Find the magnitude of the impedance |Z|.

V = 120 V (rms)f = 50 HzR = 25 ΩL = 20 mH
|Z| = Ω
2.Easy
24 V60 HzR = 60 ΩL = 100 mHI

A series RL circuit is connected to a 24 V (rms), 60 Hz supply. Find the rms current I.

V = 24 V (rms)f = 60 HzR = 60 ΩL = 100 mH
I = A
3.Medium
230 V500 HzR = 100 ΩL = 150 mHC = 2.2 µFI

A series RLC circuit is connected to a 230 V (rms), 500 Hz supply. Find the rms current I.

V = 230 V (rms)f = 500 HzR = 100 ΩL = 150 mHC = 2.2 µF
I = A
4.Medium
12 V100 HzR = 25 ΩL = 100 mHC = 47 µF

A series RLC circuit is connected to a 12 V (rms), 100 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 12 V (rms)f = 100 HzR = 25 ΩL = 100 mHC = 47 µF
φ = °
5.Hard
12 V200 HzR = 15 ΩL = 20 mHC = 4.7 µF+−VC​

A series RLC circuit is connected to a 12 V (rms), 200 Hz supply. Find the rms voltage VC across the capacitor.

V = 12 V (rms)f = 200 HzR = 15 ΩL = 20 mHC = 4.7 µF
VC = V
6.Hard
120 V50 HzR1​ = 20 ΩR2​ = 20 ΩC = 47 µFI

A resistor R1 is connected in series with a parallel combination of R2 and a capacitor C, across a 120 V (rms), 50 Hz supply. Find the rms current I.

V = 120 V (rms)f = 50 HzR1 = 20 ΩR2 = 20 ΩC = 47 µF
I = A

Answer key

  1. 1. |Z| = 25.78 Ω
  2. 2. I = 0.3387 A
  3. 3. I = 0.6735 A
  4. 4. φ = 49.21 °
  5. 5. VC = 14.02 V
  6. 6. I = 3.095 A

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