The primary and secondary coils of a transformer have 50 and 1500...

The primary and secondary coils of a transformer have 50 and 1500 turns respectively. If the magnetic flux $\phi$ linked with the primary coil is given by $\phi=\phi_0+4 t$, where $\phi$ is in weber, $t$ is time in second and $\phi_0$ is a constant, the output voltage across the secondary coil is