An alternating current of frequency 200 rad/sec and peak value 1A as shown in the figure, is applied to the primary of a transformer. If the coefficient of mutual induction between the primary and the secondary is 1.5 H, the voltage induced in the secondary will be

≈ 191 V

Use $e_s = M\,\dfrac{di}{dt}$

The current is triangular of peak $I_0=1\ \mathrm{A}$ and angular frequency $\omega=200\ \mathrm{rad\,s^{-1}}$ $(T=2\pi/\omega)$.
For a triangular wave, $|di/dt|=\dfrac{4I_0}{T}=\dfrac{2 I_0 \omega}{\pi}$