A coil of inductance 10 H and resistance 40 ohm is connected in series with a capacitance and supplied by a source of variable frequency. If the maximum current is found at frequency 1000 rad/sec, then Q-factor of the circuit will be _________.

Correct option is D

$$\text{Given:} \\[4pt]\bullet \; \text{Inductance } L = 10\,\text{H} \\[4pt]\bullet \; \text{Resistance } R = 40\,\Omega \\[4pt]\bullet \; \text{Angular frequency } \omega = 1000\,\text{rad/sec} \\[8pt]\text{The Quality Factor (QF) is given by the formula:} \\[4pt]QF = \frac{\omega L}{R} \\[8pt]\text{Substitute the given values into the formula:} \\[4pt]QF = \frac{1000 \times 10}{40} \\[4pt]QF = \frac{10000}{40} = 250 \\[8pt]\text{So, the quality factor } QF \text{ of the circuit is } 250.$$​​