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 = 60 ΩL = 250 mH

A series RL circuit is connected to a 10 V (rms), 60 Hz supply. Find the rms voltage VR across the resistor.

V = 10 V (rms)f = 60 HzR = 60 ΩL = 250 mH
VR = V
2.Easy
120 V50 HzR = 50 ΩL = 250 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 = 50 ΩL = 250 mH
|Z| = Ω
3.Medium
Vf0​ = 5000 HzRL = ?C = 4.7 µF

A series RLC circuit with C = 4.7 µF must resonate at 5000 Hz. Find the inductance L needed.

f0 = 5000 HzC = 4.7 µF
L = mH
4.Medium
100 V60 HzR = 25 ΩC = 100 µFI

A resistor and a capacitor are connected in parallel across a 100 V (rms), 60 Hz supply. Find the magnitude of the impedance |Z|.

V = 100 V (rms)f = 60 HzR = 25 ΩC = 100 µF
|Z| = Ω
5.Hard
VfR = 10 ΩL = 200 mHC = 0.1 µF

A series RLC circuit has R = 10 Ω, L = 200 mH and C = 0.1 µF. Find its quality factor Q at resonance.

R = 10 ΩL = 200 mHC = 0.1 µF
Q =
6.Hard
230 V60 HzR = 25 ΩL = 20 mHC = 22 µF+−VC​

A series RLC circuit is connected to a 230 V (rms), 60 Hz supply. Find the rms voltage VC across the capacitor.

V = 230 V (rms)f = 60 HzR = 25 ΩL = 20 mHC = 22 µF
VC = V

Answer key

  1. 1. VR = 5.37 V
  2. 2. |Z| = 93.1 Ω
  3. 3. L = 0.2156 mH
  4. 4. |Z| = 18.19 Ω
  5. 5. Q = 141.4
  6. 6. VC = 239.6 V

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