Total opposition to current flow in an AC circuit is defined as what?

Total opposition to current flow in an AC circuit is defined as impedance. Impedance is a comprehensive term that encompasses both resistance and reactance. It is measured in ohms and represents how much a circuit resists the flow of alternating current. Unlike direct current, where only resistance is considered, AC circuits involve the effects of inductance and capacitance, which introduce reactance. This means that impedance effectively accounts for all forms of opposition in the circuit, making it essential for analyzing and designing AC circuits.

In contrast, the other terms do not accurately represent total opposition in an AC context. Amperes refers to the measure of electric current. Flux density relates to the distribution of magnetic fields and is not applicable to electrical opposition. Reaction is typically a term used in the context of reactive components but does not describe the total opposition encountered in an AC circuit. Thus, impedance is the correct answer as it fully captures the essence of opposition to current in AC environments.