• # question_answer Power dissipated in an LCR series circuit connected to an a.c. source of emf E is- A) ${{E}^{2}}R/\left[ {{R}^{2}}+{{\left( L\omega -\frac{1}{C\omega } \right)}^{2}} \right]$B) $\frac{{{E}^{2}}\sqrt{{{R}^{2}}+{{\left( L\omega -\frac{1}{C\omega } \right)}^{2}}}}{R}$C) $\frac{{{E}^{2}}\left[ {{R}^{2}}+{{\left( L\omega -\frac{1}{C\omega } \right)}^{2}} \right]}{R}$D) $\frac{{{E}^{2}}R}{\sqrt{{{R}^{2}}+{{\left( L\omega -\frac{1}{C\omega } \right)}^{2}}}}$

$P=\frac{{{E}_{0}}{{I}_{0}}}{2}\,\,\cos \,\phi$ $=\,\,{{E}_{rms}}\,\,{{I}_{rms}}\,\,\times \frac{R}{Z}\,\,=\,\,\frac{{{E}^{2}}R}{{{R}^{2}}+{{\left( \omega L-\frac{1}{\omega C} \right)}^{2}}}$