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.

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1.Easy
Vf = ?L = 10 mH

At what frequency f does a 10 mH inductor have a reactance of 200 Ω?

L = 10 mHXL = 200 Ω
f = Hz
2.Easy
24 V60 HzR = 20 ΩL = 200 mHI

A series RL circuit is connected to a 24 V (rms), 60 Hz supply. Find the rms current I.

V = 24 V (rms)f = 60 HzR = 20 ΩL = 200 mH
I = A
3.Medium
120 V50 HzR = 40 ΩC = 100 µFI

A resistor and a capacitor are connected in parallel across a 120 V (rms), 50 Hz supply. Find the magnitude of the impedance |Z|.

V = 120 V (rms)f = 50 HzR = 40 ΩC = 100 µF
|Z| = Ω
4.Medium
230 V100 HzR = 100 ΩC = 4.7 µFI

A resistor and a capacitor are connected in parallel across a 230 V (rms), 100 Hz supply. Find the magnitude of the impedance |Z|.

V = 230 V (rms)f = 100 HzR = 100 ΩC = 4.7 µF
|Z| = Ω
5.Hard
24 V500 HzR1​ = 20 ΩR2​ = 80 ΩC = 10 µF

A resistor R1 is connected in series with a parallel combination of R2 and a capacitor C, across a 24 V (rms), 500 Hz supply. Find the magnitude of the impedance |Z|.

V = 24 V (rms)f = 500 HzR1 = 20 ΩR2 = 80 ΩC = 10 µF
|Z| = Ω
6.Hard
50 V60 HzR1​ = 10 ΩR2​ = 150 ΩC = 10 µFI

A resistor R1 is connected in series with a parallel combination of R2 and a capacitor C, across a 50 V (rms), 60 Hz supply. Find the rms current I.

V = 50 V (rms)f = 60 HzR1 = 10 ΩR2 = 150 ΩC = 10 µF
I = A

Answer key

  1. 1. f = 3183 Hz
  2. 2. I = 0.3077 A
  3. 3. |Z| = 24.91 Ω
  4. 4. |Z| = 95.91 Ω
  5. 5. |Z| = 41.38 Ω
  6. 6. I = 0.3588 A

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