National Council of Examiners for Engineering and Surveying (NCEES) Fundamentals of Engineering (FE) Electrical and Computer Practice Exam

The condition where capacitive reactance equals inductive reactance is termed resonance. At resonance, the reactive components of a circuit cancel each other out, resulting in a purely resistive load. This occurs in an alternating current (AC) circuit when the frequency of the supply voltage aligns with the natural frequency of the circuit, specifically where the inductive and capacitive reactances balance each other out, leading to an overall impedance that is at its minimum.

In a resonant circuit, the energy oscillates between the inductor and capacitor, allowing for maximum current flow at the resonant frequency. This phenomenon is crucial in various applications, such as tuning radios and designing filters, where precise control of frequency response is required. Understanding resonance is essential for engineers working with AC circuits, as it plays a significant role in the behavior and efficiency of electrical systems.