Question 3-29D3

At **resonance** in a series RLC circuit, the inductive reactance ($X_L$) and capacitive reactance ($X_C$) are equal in magnitude and 180 degrees out of phase. This causes them to effectively cancel each other out, leading to a very low total impedance (ideally just the resistance). A low impedance allows a large current to flow through the circuit. Even though the reactive voltages $V_L = I \times X_L$ and $V_C = I \times X_C$ are also 180 degrees out of phase and sum to zero across the reactive part, their *individual magnitudes* can become much larger than the applied source voltage due to the large current flowing through potentially high reactances. This phenomenon is called voltage magnification or Q-magnification, where significant energy oscillates between the inductor and capacitor. Resistance (A) and conductance (B) are measures of opposition to current flow but do not explain voltage magnification. Capacitance (C) is a component, but the magnification effect only occurs when it interacts with inductance at a specific frequency, i.e., at resonance.