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 = 25 ΩL = 20 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 = 25 ΩL = 20 mH
I = A
2.Easy
10 V100 HzR = 50 ΩL = 200 mH

A series RL circuit is connected to a 10 V (rms), 100 Hz supply. Find the rms voltage VR across the resistor.

V = 10 V (rms)f = 100 HzR = 50 ΩL = 200 mH
VR = V
3.Medium
230 V500 HzR = 10 ΩL = 50 mHC = 47 µFI

A series RLC circuit is connected to a 230 V (rms), 500 Hz supply. Find the rms current I.

V = 230 V (rms)f = 500 HzR = 10 ΩL = 50 mHC = 47 µF
I = A
4.Medium
Vf0​ = 50 HzRL = 100 mHC = ?

A series RLC circuit with L = 100 mH must resonate at 50 Hz. Find the capacitance C needed.

f0 = 50 HzL = 100 mH
C = µF
5.Hard
VfR = 50 ΩL = 20 mHC = 0.47 µF

A series RLC circuit has R = 50 Ω, L = 20 mH and C = 0.47 µF. Find its bandwidth B (the width of the band between the half-power frequencies), in Hz.

R = 50 ΩL = 20 mHC = 0.47 µF
B = Hz
6.Hard
100 V50 HzR1​ = 20 ΩR2​ = 30 ΩC = 100 µF

A resistor R1 is connected in series with a parallel combination of R2 and a capacitor C, across a 100 V (rms), 50 Hz supply. Find the magnitude of the impedance |Z|.

V = 100 V (rms)f = 50 HzR1 = 20 ΩR2 = 30 ΩC = 100 µF
|Z| = Ω

Answer key

  1. 1. I = 4.596 A
  2. 2. VR = 3.697 V
  3. 3. I = 1.527 A
  4. 4. C = 101.3 µF
  5. 5. B = 397.9 Hz
  6. 6. |Z| = 38.89 Ω

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