When the current flowing through one coil changes from $0 \mathrm{Amp}$ to $15 \mathrm{Amp}$ in $0.2 \mathrm{s}$, an emf of $750 \mathrm{V}$ is induced in an adjacent coil. Calculate the coefficient of mutual inductance of the two coils.

The figure below shows a metallic rod MN of length $l=80 \mathrm{cm}$, kept in a uniform magnetic field of flux density $\mathrm{B}=0.5 \mathrm{T}$, on two parallel rails P and Q. Calculate the emf that will be induced between its two ends, when it is moved towards the right with a constant velocity $v$ of $36 \mathrm{km}/\mathrm{hr}$.

When the current flowing through one coil changes from $0 \mathrm{Amp}$ to $15 \mathrm{Amp}$ in $0.2 \mathrm{s}$, an emf of $750 \mathrm{V}$ is induced in an adjacent coil. Calculate the coefficient of mutual inductance of the two coils.