Which phenomenon occurs when the inductive and capacitive reactance are equal?

Which phenomenon occurs when the inductive and capacitive reactance are equal?

• A. Impedance
• B. Reactance
• C. Resonance
• D. Attenuation

Answer: (C)

When the inductive reactance equals the capacitive reactance, their reactive effects cancel each other, leaving an impedance that is purely resistive. This condition is called resonance. It occurs at a specific frequency f0 given by f0 = 1/(2π√(LC)). At this frequency, the energy oscillates between the magnetic field of the inductor and the electric field of the capacitor, so the circuit responds very strongly to that one frequency. In a series circuit, the total impedance is minimized (essentially only the resistance remains), leading to maximum current at resonance. In a parallel circuit, the impedance is maximized, causing a strong selectivity around that frequency. This is the fundamental reason LC networks are used as tuners and filters.

When the inductive reactance equals the capacitive reactance, their reactive effects cancel each other, leaving an impedance that is purely resistive. This condition is called resonance. It occurs at a specific frequency f0 given by f0 = 1/(2π√(LC)). At this frequency, the energy oscillates between the magnetic field of the inductor and the electric field of the capacitor, so the circuit responds very strongly to that one frequency. In a series circuit, the total impedance is minimized (essentially only the resistance remains), leading to maximum current at resonance. In a parallel circuit, the impedance is maximized, causing a strong selectivity around that frequency. This is the fundamental reason LC networks are used as tuners and filters.