LC resonant frequency: 100µH × 100nF = 50.3kHz
Worked answer for an ideal LC tank built from a 100µH inductor and a 100nF capacitor.
Resonant frequency f0 50.3 kHz characteristic impedance Z0 = 31.62 Ω
| Inductance (L) | 100µH |
| Capacitance (C) | 100nF |
| Resonant frequency f0 = 1/(2π√(LC)) | 50.3 kHz |
| Characteristic impedance Z0 = √(L/C) | 31.62 Ω |
At 50.3 kHz the inductive reactance equals the capacitive reactance (XL = XC), so the tank stores energy at resonance. Halving either L or C raises f0 by a factor of √2 (≈ 1.41×).
Different values? Change L, C or solve for any quantity in the interactive tool:
Open the LC Resonant Frequency Calculator →Disclaimer: This assumes an ideal, lossless LC tank. Real inductors and capacitors have series resistance and parasitics (ESR, self-capacitance, lead inductance) that shift the actual resonant frequency and damp the response. Confirm against your components and measurements.