Q 12-07-025NEETJEE MainEasy
The resonant frequency of a series LCR circuit is $f_0$. If both L and C are doubled, the new resonant frequency is
Answer: (D) $\dfrac{f_0}{2}$
Concept. $f_0 \propto \dfrac{1}{\sqrt{LC}}$.
Step 1. Double both. $LC \to 4LC$, so $f_0 \to \dfrac{f_0}{2}$.
Answer. $\dfrac{f_0}{2}$ (Option D).
Solution by Sreeraj P, M.Sc Physics