Q142 / 180 · JIPMER 2018 · Physics
In a L-C circuit, angular frequency at resonance is $\omega$. What will be the new angular frequency when inductor's inductance is made two times and capacitor's capacitance is made four times?
- Correct answerA$\frac{\omega}{2 \sqrt{2}}$
- B$\frac{\omega}{\sqrt{2}}$
- C$2 \omega$
- D$\frac{2 \omega}{\sqrt{2}}$
Solution
$\because$ Angular frequency at resonance,
$\omega=\frac{1}{\sqrt{\mathrm{LC}}}$ ...(i)
According to question, when inductor's inductance is made 2 times and capacitance is 4 times, then
$\omega^{\prime}=\frac{1}{\sqrt{\mathrm{LC}}}$
or $\quad \omega^{\prime}=\left(\frac{1}{2 \sqrt{2}}\right) \frac{1}{\sqrt{\mathrm{LC}}}$
$=\frac{\omega}{2 \sqrt{2}} \quad$ [From Eq. (i)]
Hence, the correct answer is option: 'A'.