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 = 80 ΩL = 250 mHI

A series RL circuit is connected to a 120 V (rms), 50 Hz supply. Find the rms current I.

V = 120 V (rms)f = 50 HzR = 80 ΩL = 250 mH
I = A
2.Easy
120 V60 HzR = 50 ΩL = 250 mHI

A series RL circuit is connected to a 120 V (rms), 60 Hz supply. Find the rms current I.

V = 120 V (rms)f = 60 HzR = 50 ΩL = 250 mH
I = A
3.Medium
230 V100 HzR = 40 ΩL = 50 mHI

A resistor and an inductor are connected in parallel across a 230 V (rms), 100 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 230 V (rms)f = 100 HzR = 40 ΩL = 50 mH
φ = °
4.Medium
50 V500 HzR = 50 ΩL = 150 mHC = 22 µFI

A series RLC circuit is connected to a 50 V (rms), 500 Hz supply. Find the real power P taken from the supply.

V = 50 V (rms)f = 500 HzR = 50 ΩL = 150 mHC = 22 µF
P = W
5.Hard
10 Vf0​R = 10 ΩL = 200 mHC = 4.7 µF

A series RLC circuit is driven by a 10 V (rms) source whose frequency is set to the resonant frequency of the circuit. Find the rms voltage VL across the inductor.

V = 10 V (rms)R = 10 ΩL = 200 mHC = 4.7 µF
VL = V
6.Hard
24 Vf0​R = 20 ΩL = 20 mHC = 1 µF

A series RLC circuit is driven by a 24 V (rms) source whose frequency is set to the resonant frequency of the circuit. Find the rms voltage VL across the inductor.

V = 24 V (rms)R = 20 ΩL = 20 mHC = 1 µF
VL = V

Answer key

  1. 1. I = 1.07 A
  2. 2. I = 1.125 A
  3. 3. φ = 51.85 °
  4. 4. P = 0.592 W
  5. 5. VL = 206.3 V
  6. 6. VL = 169.7 V

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