What is resonance defined as in electrical circuits?

Resonance in electrical circuits is primarily defined by frequency. When an electrical system, such as a circuit with inductance and capacitance, is subjected to a specific frequency known as the resonant frequency, the inductive reactance and capacitive reactance become equal in magnitude but opposite in phase. At this frequency, the circuit can oscillate with maximum amplitude, and energy is efficiently transferred between the inductance and capacitance.

This phenomenon is crucial in various applications, including tuning circuits in radios, where the goal is to select and amplify a particular frequency. The concept of resonance helps in designing circuits that can filter out unwanted frequencies or enhance desired signals, making it foundational in electrical engineering.

Impedance refers to the total opposition that a circuit presents to alternating current, but it encompasses more than just frequency, as it involves resistance and reactance as well. Voltage and current are electrical quantities that are affected by resonance but do not define the concept.