State Lenz's law. Give one example to illustrate this law. The “Lenz’s law is a consequence of the law of conservation of energy”. Justify this statement.

A rectangular coil of area $A$, having number of turns $N$ is rotated at ‘$f$’ revolutions per second in a uniform magnetic field $B$, the field being perpendicular to the coil. Prove that the maximum emf induced in the coil is $2\pi f NBA$.

Or

A coil of number of turns $N$, area $A$ is rotated at a constant angular speed $\omega$ in a uniform magnetic field $B$ and connected to a resistor $R$. Deduce expressions for: (i) Maximum emf induced in the coil (ii) Power dissipation in the coil.

A rectangular coil of area $A$, having number of turns $N$ is rotated at ‘$f$’ revolutions per second in a uniform magnetic field $B$, the field being perpendicular to the coil. Prove that the maximum emf induced in the coil is $2\pi f NBA$.

Or

A coil of number of turns $N$, area $A$ is rotated at a constant angular speed $\omega$ in a uniform magnetic field $B$ and connected to a resistor $R$. Deduce expressions for:  Power dissipation in the coil.