Question

two neighboring coils. A and B have mutual inductance of 20 mH. The current flowing through A is given by $i=3t^2-4t+6.$ The induced emf at t = 2s is:

• A. $100mV$
• B. $160mV$
• C. 260 mV
• D. 300 mV

Answer 1

The correct option is B $160mV$

$\begin{array}{c}\varphi =ui\\ =20\times {10}^{-3}\left[3t^2-4t+6\right]\\ E=\left|\frac{d\varphi }{dt}\right|=20\times {10}^{-3}\left[6t-4\right]\\ att=2\\ E=20\times {10}^{-3}\times 8\\ =160mv\end{array}$

$\therefore$ Option $B$ is correct.