When considering voltages, currents and powers in AC circuits we need to take into account other issues including inductance, capacitance as well as resistance. Different loads have different characteristics.

The effect that capacitive and inductive loads have on an AC circuit is that they cause a shift in phase between the voltage and currents of a circuit. These loads posses a quality called reactance, this is the opposition to current flow that a component like a capacitor or inductor have. Loads with capacitive or inductive loads are called reactive loads.