resonant circuit

/ rĕz′ə-nənt /

1. An electric circuit which has very low impedance at a certain frequency. Resonant circuits are often built using an inductor, such as a coil, connected in parallel to a capacitor. The response of the circuit to signals of different frequencies is a function of the inductance and capacitance of the circuit and peaks at one frequency value, at which the current flow resonates most strongly with the input signal. Resonant circuits are used in radio and television tuners to pick out broadcast signals of specific frequencies.