# Formula Maximum current in resonant RLC series circuit Peak voltage    Ohmic resistance    Inductance    Capacitance    Angular frequency ## Peak current

Unit
This is the maximum current (also called peak current) flowing through a RLC series circuit. Of course, the current $$I(t)$$ oscillates periodically with time, but $$I_0$$ indicates the peak value.

The formula is similar to Ohm's law, except that instead of Ohm's resistance $$R$$ we have the magnitude of the impedance $$| Z |$$:$$| Z | ~=~ \sqrt{ R^2 ~+~ \left( \omega \, L ~-~ \frac{1}{\omega \, C} \right)^2 }$$

Thus, we can also write the maximum current as follows:$$I_0 ~=~ \frac{ U_0 }{ | Z | }$$

## Peak voltage

Unit
Also the voltage $$U(t)$$ oscillates periodically with time, but $$U_0$$ represents the maximum value, i.e. the peak voltage. This can be, for example, the amplitude of the applied AC voltage.

## Ohmic resistance

Unit
The ohmic resistance in the RLC series circuit. The larger the resistance, the smaller the maximum possible current $$I_0$$.

## Inductance

Unit
The inductance of the coil in the RLC series circuit. Together with the angular frequency $$\omega$$ it forms the inductive reactance: $$X_{\text L} = \omega \, L$$.

## Capacitance

Unit
The electrical capacitance of the capacitor in the RLC series circuit. Together with the angular frequency $$\omega$$ it forms the capacitive reactance: $$X_{\text C} = - \frac{1}{ \omega \, C }$$.

## Angular frequency

Unit
The angular frequency describes indirectly by the relation $$\omega = 2\pi \, f$$ with which frequency $$f$$ the voltages at the $$R$$, $$L$$ and $$C$$ elements and the current $$I$$ change. This frequency is given by the applied AC voltage $$U(t)$$.