The magnetic flux passing perpendicular to the plane of coil is changing according to the equation $\Phi = 6t^2+7t + 1$, where '$\Phi$' is in mWb and 't' in sec. The magnitude of induced emf at t = 2s is

31 mV 38 mV 39 mV 32 mV

31 mV

The magnitude of induced emf $ \xi = \frac{d\Phi}{dt} = 12t + 7$ At t = 2s , $ \xi = 31V$