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
V500 HzL = 5 mH

Find the reactance XL of a 5 mH inductor at 500 Hz.

L = 5 mHf = 500 Hz
XL = Ω
2.Easy
230 V100 HzR = 80 ΩC = 100 µF

A series RC circuit is connected to 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 = 80 ΩC = 100 µF
φ = °
3.Medium
50 V50 HzR = 20 ΩL = 20 mHC = 47 µFI

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

V = 50 V (rms)f = 50 HzR = 20 ΩL = 20 mHC = 47 µF
I = A
4.Medium
Vf0​ = 5000 HzRL = ?C = 0.22 µF

A series RLC circuit with C = 0.22 µF must resonate at 5000 Hz. Find the inductance L needed.

f0 = 5000 HzC = 0.22 µF
L = mH
5.Hard
10 V200 HzR = 25 ΩL = 100 mHC = 2.2 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 = 25 ΩL = 100 mHC = 2.2 µF
I = A
6.Hard
10 Vf0​R = 5 ΩL = 100 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 = 5 ΩL = 100 mHC = 4.7 µF
VL = V

Answer key

  1. 1. XL = 15.71 Ω
  2. 2. φ = −11.25 °
  3. 3. I = 0.7738 A
  4. 4. L = 4.606 mH
  5. 5. I = 0.04213 A
  6. 6. VL = 291.7 V

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