Question

A capacitor of capacitance, $C=25\mu \text{F}$ is fully charged to $300\text{V}$. It is then connected across a $10\text{mH}$ inductor. The resistance in the circuit is negligible. Find the frequency of oscillation of the current in the circuit.

• A. $220\text{Hz}$
• B. $270\text{Hz}$
• C. $318\text{Hz}$
• D. $412\text{Hz}$

Answer 1

The correct option is C $318\text{Hz}$

The frequency of oscillation of the current in the LC circuit is,

$f=\frac{1}{2\pi \sqrt{LC}}$

$\Rightarrow f=\frac{1}{2\times 3.14\times \sqrt{10\times {10}^{-3}\times 25\times {10}^{-6}}}\approx 318\text{Hz}$

Hence, option $\left(C\right)$ is the correct answer.