RE-NEET 2026 Physics LCR Circuits MCQ Question

To find the current amplitude in the LCR circuit, we first determine the impedance $Z$ using the formula:

$Z = \sqrt{R^2 + \left( X_L - X_C \right)^2}$

where $X_L = \omega L$ and $X_C = \frac{1}{\omega C}$. Here, $\omega = 2 \times 10^3 \, \text{rad/s}$, $L = 10 \, \text{mH} = 10 \times 10^{-3} \, \text{H}$, and $C = 25 \, \mu\text{F} = 25 \times 10^{-6} \, \text{F}$.

Calculating $X_L$ and $X_C$:

$X_L = 2 \times 10^3 \times 10 \times 10^{-3} = 20 \, \Omega$ $X_C = \frac{1}{2 \times 10^3 \times 25 \times 10^{-6}} = 20 \, \Omega$

Thus, $X_L - X_C = 0$, leading to:

$Z = R = 100 \, \Omega$

The current amplitude $I_0$ is given by:

$I_0 = \frac{V_0}{Z} = \frac{220}{100} = 2.2 \, A$

The tempting wrong options fail because they miscalculate the impedance or the current amplitude.