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 worksheet Practise 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

A series RL circuit is connected to a 230 V (rms), 100 Hz supply. Find the rms voltage V_L across the inductor.

V = 230 V (rms)f = 100 HzR = 100 ΩL = 150 mH

V_L = V

2.Easy

A series RL circuit is connected to a 12 V (rms), 60 Hz supply. Find the magnitude of the impedance |Z|.

V = 12 V (rms)f = 60 HzR = 10 ΩL = 250 mH

|Z| = Ω

3.Medium

A series RLC circuit is connected to a 12 V (rms), 200 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 12 V (rms)f = 200 HzR = 60 ΩL = 100 mHC = 100 µF

φ = °

4.Medium

A resistor and a capacitor are connected in parallel across a 120 V (rms), 60 Hz supply. Find the phase angle φ of the impedance, in degrees (positive when the current lags the voltage).

V = 120 V (rms)f = 60 HzR = 10 ΩC = 100 µF

φ = °

5.Hard

A series RLC circuit is connected to a 120 V (rms), 200 Hz supply. Find the resonant frequency f₀ of the circuit.

V = 120 V (rms)f = 200 HzR = 50 ΩL = 50 mHC = 4.7 µF

f₀ = Hz

6.Hard

A resistor R₁ is connected in series with a parallel combination of R₂ and a capacitor C, across a 12 V (rms), 60 Hz supply. Find the rms current I.

V = 12 V (rms)f = 60 HzR₁ = 40 ΩR₂ = 20 ΩC = 47 µF

I = A

Answer key

1. V_L = 157.7 V
2. |Z| = 94.78 Ω
3. φ = 62.99 °
4. φ = −20.66 °
5. f₀ = 328.3 Hz
6. I = 0.2065 A

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