在LC电路中，L代表电感，单位：亨利（H），C代表电容，单位：法拉（F）。

电磁振荡完成一次周期性变化需要的时间叫做周期，一秒内完成的周期性变化的次数叫做频率。

振荡电路中发生电磁振荡时，如果没有能量损失，也不受其他外界的影响，这是电磁振荡的周期和频率，叫做振荡电路的固有频率和固有周期。固有周期可以用下式求得

其时间常数为L/R.

An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, is an electric circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together. The circuit can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.