Resonant Frequency Calculator
The resonant frequency of an LC circuit is the frequency at which the inductor and capacitor exchange energy with maximum efficiency, causing the circuit to oscillate. It is determined by the formula f = 1/(2π√(LC)). This calculator computes resonant frequency, angular frequency, and impedance behavior at resonance.
An LC circuit consists of an inductor (L) and a capacitor (C) connected together. At the resonant frequency, the inductive reactance XL = ωL equals the capacitive reactance XC = 1/(ωC), and the two cancel each other. The result depends on the circuit configuration.
In a series LC circuit, the impedance drops to zero at resonance (or to just the resistance in a real RLC circuit), allowing maximum current flow. In a parallel LC circuit, the impedance reaches a theoretical maximum (infinity for ideal components), blocking current at the resonant frequency. This is the operating principle of bandpass and band-stop filters.
LC resonance is fundamental to radio tuning, oscillators, filters, and impedance matching networks. AM radios use variable capacitors to tune the LC circuit's resonant frequency to different broadcast stations. The formula f = 1/(2π√(LC)) was derived by William Thomson (Lord Kelvin) in 1853 and remains one of the most important equations in electrical engineering.