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
12 V1000 HzR = 100 ΩC = 10 µF

A series RC circuit is connected to a 12 V (rms), 1000 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 12 V (rms)f = 1000 HzR = 100 ΩC = 10 µF
φ = °
2.Easy
120 V60 HzR = 100 ΩL = 20 mH

A series RL circuit is connected to a 120 V (rms), 60 Hz supply. Find the magnitude of the impedance |Z|.

V = 120 V (rms)f = 60 HzR = 100 ΩL = 20 mH
|Z| = Ω
3.Medium
Vf0​ = 500 HzRL = 10 mHC = ?

A series RLC circuit with L = 10 mH must resonate at 500 Hz. Find the capacitance C needed.

f0 = 500 HzL = 10 mH
C = µF
4.Medium
230 V100 HzR = 60 ΩL = 100 mHC = 4.7 µF

A series RLC 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 = 60 ΩL = 100 mHC = 4.7 µF
φ = °
5.Hard
100 V50 HzR = 60 ΩL = 200 mHC = 10 µFI

A series RLC circuit is connected to a 100 V (rms), 50 Hz supply. Find the rms current I.

V = 100 V (rms)f = 50 HzR = 60 ΩL = 200 mHC = 10 µF
I = A
6.Hard
10 V50 HzR = 50 ΩL = 250 mHC = 10 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 = 250 mHC = 10 µF
I = A

Answer key

  1. 1. φ = −9.043 °
  2. 2. |Z| = 100.3 Ω
  3. 3. C = 10.13 µF
  4. 4. φ = −77.73 °
  5. 5. I = 0.3811 A
  6. 6. I = 0.04083 A

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