Question

For the tank circuit shown in figure below, the resonant frequency is

• A. 158.35 Hz
• B. 138.35 Hz
• C. 148.35 Hz
• D. 128.35 Hz

Answer 1

The correct option is A 158.35 Hz

The resonant frequency,
$f_r=\frac{1}{2\pi }\sqrt{\frac{1}{LC}-\frac{R^2}{L^2}}$
$=\frac{1}{2\pi }\sqrt{\frac{1}{0.1\times 10\times {10}^{-6}}-\frac{(10{)}^2}{(0.1{)}^2}}$
$=\frac{1}{2\pi }\sqrt{{10}^6-{10}^4}=\frac{1}{2\pi }\left(994.98\right)$
$=158.35Hz$