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.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
10 V60 HzR = 20 ΩL = 250 mHI

A series RL circuit is connected to a 10 V (rms), 60 Hz supply. Find the rms current I.

V = 10 V (rms)f = 60 HzR = 20 ΩL = 250 mH
I = A
2.Easy
50 V50 HzR = 40 ΩL = 50 mH

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

V = 50 V (rms)f = 50 HzR = 40 ΩL = 50 mH
VL = V
3.Medium
100 V100 HzR = 40 ΩL = 200 mHC = 47 µFI

A series RLC circuit is connected to a 100 V (rms), 100 Hz supply. Find the real power P taken from the supply.

V = 100 V (rms)f = 100 HzR = 40 ΩL = 200 mHC = 47 µF
P = W
4.Medium
230 V200 HzR = 15 ΩL = 150 mHC = 22 µF

A series RLC circuit is connected to a 230 V (rms), 200 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 230 V (rms)f = 200 HzR = 15 ΩL = 150 mHC = 22 µF
φ = °
5.Hard
VfR = 50 ΩL = 2 mHC = 0.22 µF

A series RLC circuit has R = 50 Ω, L = 2 mH and C = 0.22 µF. Find its quality factor Q at resonance.

R = 50 ΩL = 2 mHC = 0.22 µF
Q =
6.Hard
120 V100 HzR1​ = 30 ΩR2​ = 150 ΩC = 4.7 µF

A resistor R1 is connected in series with a parallel combination of R2 and a capacitor C, across a 120 V (rms), 100 Hz supply. Find the magnitude of the impedance |Z|.

V = 120 V (rms)f = 100 HzR1 = 30 ΩR2 = 150 ΩC = 4.7 µF
|Z| = Ω

Answer key

  1. 1. I = 0.1038 A
  2. 2. VL = 18.28 V
  3. 3. P = 39.89 W
  4. 4. φ = 84.38 °
  5. 5. Q = 1.907
  6. 6. |Z| = 165 Ω

Full step-by-step solutions: practise this topic on examproblems.com.