• # question_answer Two coil have a mutual inductance$0.005\text{ }H$. The current changes in first coil according to equation $I={{I}_{0}}\sin \omega t$ where ${{I}_{0}}=2A$ and $\omega =100\pi$ rad/sec. The maximum value of emf in second coil is A)  $4\pi$                       B)  $3\pi$C)  $2\pi$                       D)  $\pi$

$e=M\frac{di}{dt}=0.005\times \frac{d}{dt}({{i}_{0}}\sin \omega t)=0.005\,{{i}_{0}}\,\omega \,\cos \,\omega t$ $={{e}_{0}}\,\cos \,\omega t$   $\therefore$ ${{e}_{\max }}=0.005\times 2\times 100\pi =\pi$