LC resonance, Q factor & bandwidth worksheet with answers

Free printable LC resonance, Q factor & bandwidth 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
C = 100 nF+−20 VL = 100 µHiL​

A 100 nF capacitor charged to 20 V is switched across an ideal 100 µH inductor. Find the peak current Imax in the circuit, in mA.

C = 100 nFV0 = 20 VL = 100 µH
Imax = mA
2.Easy
C = 470 nFL = 47 µH

An ideal LC circuit has L = 47 µH and C = 470 nF. Find its natural (resonance) frequency f0 in kHz.

L = 47 µHC = 470 nF
f0 = kHz
3.Medium
V2 Ω2.2 mH10 µF

A series RLC circuit has R = 2 Ω, L = 2.2 mH and C = 10 µF. Find its bandwidth BW in Hz.

R = 2 ΩL = 2.2 mHC = 10 µF
BW = Hz
4.Medium
tvC​iL​T/4 = ?T/2TL = 47 mHC = 100 nF

In an ideal LC circuit with L = 47 mH and C = 100 nF, the capacitor is fully charged at t = 0. How long does it take until all the energy is in the inductor? Give t in µs.

L = 47 mHC = 100 nF
t = µs
5.Hard
VR = ?10 mHC

A series resonant circuit uses a 10 mH inductor. Which total series resistance R gives a bandwidth of 500 Hz?

L = 10 mHBW = 500 Hz
R = Ω
6.Hard
V1 Ω1 mH47 nF50 mA

A series RLC circuit (R = 1 Ω, L = 1 mH, C = 47 nF) is driven at resonance with a current amplitude of 50 mA. Find the energy Ecycle dissipated in R during one cycle, in nJ.

R = 1 ΩL = 1 mHC = 47 nFIm = 50 mA
Ecycle = nJ

Answer key

  1. 1. Imax = 632.5 mA
  2. 2. f0 = 33.86 kHz
  3. 3. BW = 144.7 Hz
  4. 4. t = 107.7 µs
  5. 5. R = 31.42 Ω
  6. 6. Ecycle = 53.84 nJ

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