» This article is about electronics. For a discussion of "reactive" or "reactance" in chemistry, see reactivity.:For a discussion of the psychological concept of reactance, see reactance (psychology). Reactance is the imaginary part of electrical impedance, a measure of opposition to a sinusoidal alternating current. Reactance arises from the presence of inductance and capacitance within a circuit, and is denoted by the symbol scriptstyle phase difference) with the sinusoidal current through th… (More on Reactance)