Define 'reactance' in the context of AC circuits.

Reactance refers specifically to the resistance to the flow of alternating current (AC) caused by the presence of inductors and capacitors in a circuit. Unlike resistive components, which dissipate electrical energy as heat, inductors and capacitors store energy in the form of magnetic and electric fields, respectively. Reactance is a crucial concept in AC circuit analysis because it determines how much opposition the circuit presents to the flow of current due to these components, affecting the overall impedance of the circuit.

In this context, the role of inductors and capacitors can be summarized as follows: inductors impede changes in current, causing a phase shift between voltage and current, while capacitors impede changes in voltage in a similar manner. The combined effect of these elements results in a phase relationship between voltage and current that is vital for understanding the behavior of AC circuits. This is why the correct definition of reactance emphasizes the resistance to current flow specifically due to inductive and capacitive components.