# Capacitive Reactance

## Description

In electrical and electronic systems, reactance is the opposition of a circuit element to a change of electric current or voltage, due to that element’s inductance or capacitance. A built-up electric field resists the change of voltage on the element, while a magnetic field resists the change of current. The notion of reactance is similar to electrical resistance, but they differ in several respects.

An ideal resistor has zero reactance, while ideal inductors and capacitors consist entirely of reactance. The magnitude of the reactance of an inductor is proportional to frequency, while the magnitude of the reactance of a capacitor is inversely proportional to frequency.

Related formulas## Variables

X_{C} | capacitive reactance (ohm) |

π | pi |

f | frequency (Hz) |

C | capacitance (farad) |