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
50 V50 HzR = 25 ΩL = 20 mH

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

V = 50 V (rms)f = 50 HzR = 25 ΩL = 20 mH
VR = V
2.Easy
12 V100 HzR = 30 ΩC = 4.7 µF

A series RC 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 = 30 ΩC = 4.7 µF
φ = °
3.Medium
24 V200 HzR = 40 ΩC = 10 µFI

A resistor and a capacitor are connected in parallel across a 24 V (rms), 200 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 24 V (rms)f = 200 HzR = 40 ΩC = 10 µF
φ = °
4.Medium
12 V100 HzR = 80 ΩL = 20 mHC = 47 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 = 80 ΩL = 20 mHC = 47 µF
I = A
5.Hard
230 V50 HzR1​ = 25 ΩR2​ = 50 ΩC = 100 µFI

A resistor R1 is connected in series with a parallel combination of R2 and a capacitor C, across a 230 V (rms), 50 Hz supply. Find the rms current I.

V = 230 V (rms)f = 50 HzR1 = 25 ΩR2 = 50 ΩC = 100 µF
I = A
6.Hard
10 V50 HzR = 30 ΩL = 150 mHC = 47 µF+−VC​

A series RLC circuit is connected to a 10 V (rms), 50 Hz supply. Find the rms voltage VC across the capacitor.

V = 10 V (rms)f = 50 HzR = 30 ΩL = 150 mHC = 47 µF
VC = V

Answer key

  1. 1. VR = 48.49 V
  2. 2. φ = −84.94 °
  3. 3. φ = −26.69 °
  4. 4. I = 0.145 A
  5. 5. I = 5.059 A
  6. 6. VC = 18.61 V

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