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
10 V50 HzR = 100 ΩL = 100 mH

A series RL circuit is connected to a 10 V (rms), 50 Hz supply. Find the magnitude of the impedance |Z|.

V = 10 V (rms)f = 50 HzR = 100 ΩL = 100 mH
|Z| = Ω
2.Easy
Vf = ?L = 2.2 mH

At what frequency f does a 2.2 mH inductor have a reactance of 50 Ω?

L = 2.2 mHXL = 50 Ω
f = Hz
3.Medium
Vf0​ = 500 HzRL = ?C = 47 µF

A series RLC circuit with C = 47 µF must resonate at 500 Hz. Find the inductance L needed.

f0 = 500 HzC = 47 µF
L = mH
4.Medium
230 V200 HzR = 10 ΩL = 100 mHC = 10 µF

A series RLC circuit is connected to a 230 V (rms), 200 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 230 V (rms)f = 200 HzR = 10 ΩL = 100 mHC = 10 µF
φ = °
5.Hard
24 V60 HzR = 40 ΩL = 50 mHC = 22 µFI

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

V = 24 V (rms)f = 60 HzR = 40 ΩL = 50 mHC = 22 µF
I = A
6.Hard
10 V50 HzR = 50 ΩL = 200 mHC = 100 µFI

A series RLC circuit is connected to a 10 V (rms), 50 Hz supply. Find the rms current I.

V = 10 V (rms)f = 50 HzR = 50 ΩL = 200 mHC = 100 µF
I = A

Answer key

  1. 1. |Z| = 104.8 Ω
  2. 2. f = 3617 Hz
  3. 3. L = 2.156 mH
  4. 4. φ = 77.76 °
  5. 5. I = 0.2196 A
  6. 6. I = 0.17 A

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