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 V50 HzR = 40 ΩL = 20 mHI

A series RL circuit is connected to a 100 V (rms), 50 Hz supply. Find the rms current I.

V = 100 V (rms)f = 50 HzR = 40 ΩL = 20 mH
I = A
2.Easy
230 V500 HzR = 30 ΩC = 10 µF

A series RC circuit is connected to a 230 V (rms), 500 Hz supply. Find the magnitude of the impedance |Z|.

V = 230 V (rms)f = 500 HzR = 30 ΩC = 10 µF
|Z| = Ω
3.Medium
Vf0​ = 50 HzRL = ?C = 1 µF

A series RLC circuit with C = 1 µF must resonate at 50 Hz. Find the inductance L needed.

f0 = 50 HzC = 1 µF
L = mH
4.Medium
100 V1000 HzR = 100 ΩL = 250 mHC = 100 µF

A series RLC circuit is connected to a 100 V (rms), 1000 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 100 V (rms)f = 1000 HzR = 100 ΩL = 250 mHC = 100 µF
φ = °
5.Hard
230 V1000 HzR = 40 ΩL = 100 mHC = 47 µF+−VC​

A series RLC circuit is connected to a 230 V (rms), 1000 Hz supply. Find the rms voltage VC across the capacitor.

V = 230 V (rms)f = 1000 HzR = 40 ΩL = 100 mHC = 47 µF
VC = V
6.Hard
24 V100 HzR = 40 ΩL = 20 mHC = 2.2 µF+−VC​

A series RLC circuit is connected to a 24 V (rms), 100 Hz supply. Find the rms voltage VC across the capacitor.

V = 24 V (rms)f = 100 HzR = 40 ΩL = 20 mHC = 2.2 µF
VC = V

Answer key

  1. 1. I = 2.47 A
  2. 2. |Z| = 43.74 Ω
  3. 3. L = 10132 mH
  4. 4. φ = 86.35 °
  5. 5. VC = 1.244 V
  6. 6. VC = 24.39 V

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