Enter your Inductance (L) and Capacitance (C) — along with their units — into this Resonant Frequency Calculator, and get the Resonant Frequency your LC circuit naturally oscillates at, plus the Angular Frequency and Period.
Resonant Frequency
--
Angular Frequency
--
Period
--
An LC circuit, also called a tank circuit, is an electrical circuit consisting of an inductor (L) and capacitor (C) connected in series or parallel. It's called a tank circuit because energy oscillates back and forth between the magnetic field of the inductor and the electric field of the capacitor, similar to water sloshing in a tank.
Resonant frequency is the specific frequency at which an LC circuit naturally oscillates with maximum amplitude. At this frequency, the inductive reactance equals the capacitive reactance, causing them to cancel each other out and creating minimum impedance in the circuit.
The resonant frequency is calculated using the formula: f = 1/(2π√LC), where f is the frequency in Hz, L is the inductance in Henries, and C is the capacitance in Farads. This formula applies to both series and parallel LC circuits.
Using the formula f = 1/(2π√LC) with L = 1 mH and C = 220 pF, the resonant frequency is approximately 10.74 MHz. This is a common frequency range used in radio communications.
Radios use LC circuits tuned to specific resonant frequencies to select desired radio stations. By adjusting the inductance or capacitance, the radio can be tuned to different frequencies, allowing it to receive signals from different broadcasting stations while filtering out unwanted frequencies.
At the resonant frequency, the energy stored alternately switches between the inductor's magnetic field and the capacitor's electric field. The impedance is at its minimum for parallel circuits and maximum for series circuits, resulting in maximum current flow and power transfer.
You can use any units, but make sure they're consistent. Common combinations include millihenries (mH) with picofarads (pF) for radio frequencies, or microhenries (μH) with nanofarads (nF). The calculator automatically handles unit conversions.
This calculator specifically calculates the resonant frequency for ideal LC circuits (zero resistance). For RLC circuits with resistance, the resonant frequency remains approximately the same, but the circuit will have damping effects that reduce the amplitude of oscillations.