### Resonance in Series-Parallel Circuits

Textbook
- Vol. II - Alternating Current (AC) - Chapter 6 - Resonance

In simple reactive circuits with little or no resistance, the effects of radically altered impedance will manifest at the resonance frequency predicted by the equation given earlier. In a parallel (tank) LC circuit, this means infinite impedance at resonance. In a series LC circuit, it means zero impedance at resonance:
However, as soon as significant levels of resistance are introduced into most LC circuits, this simple calculation for resonance becomes