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
12 V50 HzR = 60 ΩL = 50 mH

A series RL circuit is connected to a 12 V (rms), 50 Hz supply. Find the magnitude of the impedance |Z|.

V = 12 V (rms)f = 50 HzR = 60 ΩL = 50 mH
|Z| = Ω
2.Easy
230 V60 HzR = 80 ΩL = 50 mHI

A series RL circuit is connected to a 230 V (rms), 60 Hz supply. Find the rms current I.

V = 230 V (rms)f = 60 HzR = 80 ΩL = 50 mH
I = A
3.Medium
10 V200 HzR = 50 ΩL = 50 mHC = 1 µFI

A series RLC circuit is connected to a 10 V (rms), 200 Hz supply. Find the rms current I.

V = 10 V (rms)f = 200 HzR = 50 ΩL = 50 mHC = 1 µF
I = A
4.Medium
50 V200 HzR = 30 ΩL = 200 mHC = 100 µFI

A series RLC circuit is connected to a 50 V (rms), 200 Hz supply. Find the power factor cos φ of the circuit.

V = 50 V (rms)f = 200 HzR = 30 ΩL = 200 mHC = 100 µF
cos φ =
5.Hard
120 V200 HzR1​ = 40 ΩR2​ = 30 ΩC = 22 µF

A resistor R1 is connected in series with a parallel combination of R2 and a capacitor C, across a 120 V (rms), 200 Hz supply. Find the magnitude of the impedance |Z|.

V = 120 V (rms)f = 200 HzR1 = 40 ΩR2 = 30 ΩC = 22 µF
|Z| = Ω
6.Hard
50 V100 HzR = 80 ΩL = 20 mHC = 2.2 µF+−VC​

A series RLC circuit is connected to a 50 V (rms), 100 Hz supply. Find the rms voltage VC across the capacitor.

V = 50 V (rms)f = 100 HzR = 80 ΩL = 20 mHC = 2.2 µF
VC = V

Answer key

  1. 1. |Z| = 62.02 Ω
  2. 2. I = 2.798 A
  3. 3. I = 0.01361 A
  4. 4. cos φ = 0.1223
  5. 5. |Z| = 59.62 Ω
  6. 6. VC = 50.56 V

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