Question

The resonant frequency of a series $LCR$ circuit with $L=2.0H$, $C=32\mu F$ and $R=10\Omega$ is

• A. $20Hz$
• B. $30Hz$
• C. $40Hz$
• D. $50Hz$

Answer 1

Answer: (A)

Here, $L=2H$,
$C=32\mu F=32\times 10^{-6}F$,
$R=10\Omega$
$\therefore {\omega }_r=\frac{1}{\sqrt{LC}}$
$=\frac{1}{\sqrt{2\times 32\times 10^{-6}}}$
$=125rad{s}^{-1}$
${\upsilon }_r=\frac{{\omega }_r}{2\pi }$
$=\frac{125}{2\times 3.14}$
$=20Hz$