A&P Aviation Mechanic Technician Practice Test

The correct answer identifies the three main causes of opposition to current flow in an alternating current (AC) circuit: resistance, inductive reactance, and capacitive reactance.

Resistance represents the opposition to the flow of electric current due to the physical properties of the circuit materials, contributing to energy loss in the form of heat. Inductive reactance arises from inductors in the circuit, opposing changes in current flow due to the magnetic fields they create. This effect is frequency-dependent, meaning that as the frequency of the AC signal increases, the inductive reactance increases as well. Capacitive reactance originates from capacitors, which store and release energy in the electric field, opposing changes in voltage across their plates. Like inductive reactance, capacitive reactance is also frequency-dependent, but it operates in the opposite manner, providing lower opposition at higher frequencies.

Together, these three components — resistance, inductive reactance, and capacitive reactance — determine the overall impedance of the circuit, which is the total opposition to current flow in an AC environment. Understanding these elements is crucial for analyzing and designing AC electrical systems effectively.