could you be more specific? are you referring to electrical reactance or magnetic reactance or Chemical reactance or even psychological reactance?
as i may add to the contribution of other members: In phasor analysis, reactance is used to compute amplitude and phase changes of sinusoidal alternating current going through the circuit element. It is denoted by the symbol *X* Both reactance *X* and resistance *R* are required to calculate the impedance *Z* . In some circuits one of these may dominate, but an approximate knowledge of the minor component is useful to determine if it may be neglected.
