Q119 / 120 · VITEEE 2014 · Physics
An $L-C-R$ circuit contains $R=50 \Omega, L=1 \mathrm{mH}$ and $\mathrm{C}=0.1 \mu \mathrm{F}$. The impedence of the circuit will be minimum for a frequency of
- Correct answerA$\frac{10^{5}}{2 \pi} \mathrm{Hz}$
- B$\frac{10^{6}}{2 \pi} \mathrm{Hz}$
- C$2 \pi \times 10^{5} \mathrm{~Hz}$
- D$2 \pi \times 10^{6} \mathrm{~Hz}$
Solution
Impedance of L-C-R circuit will be minimum for a resonant frequency so,
$\begin{aligned}
& v_{0}=\frac{1}{2 \pi \sqrt{L C}} \\
=& \frac{1}{2 \pi \sqrt{1 \times 10^{-3} \times 0.1 \times 10^{-6}}}=\frac{10^{5}}{2 \pi} \mathrm{Hz}
\end{aligned}$
Hence, the correct answer is option: 'A'.