Question

A series $LCR$ circuit of $R=5\Omega ,L=20\text{mH}$ and $C=0.5\mu \text{F}$ is connected across an $\text{AC}$ supply of $250\text{V}$, having variable frequency. The power dissipated at resonance condition is _____ $\times {10}^2\text{W}$.

• A. 125.0
• B. 125

Answer 1

Answer: (A), (B)

At resonance condition,

$Z=R(X_L-X_C=0)$

$\therefore i_{rms}=\frac{V}{Z}=\frac{V}{R}$

So, the power dissipated,

$P=\frac{V^2}{R}=\frac{250\times 250}{5}=125\times {10}^2\text{W}$

$\therefore \text{Correct answer}:125$