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
120 V60 HzR = 50 ΩL = 50 mHI

A series RL circuit is connected to a 120 V (rms), 60 Hz supply. Find the rms current I.

V = 120 V (rms)f = 60 HzR = 50 ΩL = 50 mH
I = A
2.Easy
10 V100 HzR = 20 ΩC = 10 µFI

A series RC circuit is connected to a 10 V (rms), 100 Hz supply. Find the rms current I.

V = 10 V (rms)f = 100 HzR = 20 ΩC = 10 µF
I = A
3.Medium
Vf0​ = 50 HzRL = 50 mHC = ?

A series RLC circuit with L = 50 mH must resonate at 50 Hz. Find the capacitance C needed.

f0 = 50 HzL = 50 mH
C = µF
4.Medium
230 V50 HzR = 60 ΩC = 47 µFI

A resistor and a capacitor are connected in parallel across a 230 V (rms), 50 Hz supply. Find the magnitude of the impedance |Z|.

V = 230 V (rms)f = 50 HzR = 60 ΩC = 47 µF
|Z| = Ω
5.Hard
24 Vf0​R = 5 ΩL = 5 mHC = 4.7 µF

A series RLC circuit is driven by a 24 V (rms) source whose frequency is set to the resonant frequency of the circuit. Find the rms voltage VL across the inductor.

V = 24 V (rms)R = 5 ΩL = 5 mHC = 4.7 µF
VL = V
6.Hard
VfR = 15 ΩL = 1 mHC = 0.47 µF

A series RLC circuit has R = 15 Ω, L = 1 mH and C = 0.47 µF. Find its bandwidth B (the width of the band between the half-power frequencies), in Hz.

R = 15 ΩL = 1 mHC = 0.47 µF
B = Hz

Answer key

  1. 1. I = 2.246 A
  2. 2. I = 0.06234 A
  3. 3. C = 202.6 µF
  4. 4. |Z| = 44.91 Ω
  5. 5. VL = 156.6 V
  6. 6. B = 2387 Hz

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