Answer: Q = ω_0 L/R = 1/(ω_0 CR).
- A Q = ω_0 L/R = 1/(ω_0 CR)
- B Q = R/ω_0 L under most conditions encountered
- C Q = ω_0 C/R as frequently observed in practice
- D Q = RL/ω_0 in many documented cases
Correct answer: A. Q = ω_0 L/R = 1/(ω_0 CR)
Explanation: Q = ω_0 L/R = 1/(ω_0 CR). A higher Q means sharper resonance peak and smaller bandwidth. It represents the ratio of energy stored to energy dissipated per cycle.
In a pure inductor the current lags the voltage by 90° (energy is briefly stored in the magnetic field before current responds); in a pure capacitor the current leads the voltage by 90° (current must flow to build up charge before voltage rises) - the mnemonic "ELI the ICE man" keeps these straight.
Concept context
AC circuits, impedance, LCR series circuit, resonance, transformers, and power factor.