Q109 / 150 · MHT CET 2012 · Physics
The $Q$ -factor of a resonant circuit is equal to
- A$\frac{1}{L} \sqrt{\frac{R}{C}}$
- Correct answerB$\frac{1}{R} \sqrt{\frac{L}{C}}$
- C$\frac{1}{R L} \sqrt{C}$
- D$\frac{1}{C} \sqrt{\frac{R}{L}}$
Solution
The quality factor (Q-factor) of a resonant circuit
$$
Q=\frac{\omega_{0} L}{R}
$$
At resonance, $\omega_{0}=\frac{1}{\sqrt{L C}}$
$$
Q=\frac{1}{\sqrt{L} C} \cdot \frac{L}{R}=\frac{1}{R} \sqrt{\frac{L}{C}}
$$
Hence, the correct answer is option: 'B'.