(a) State Faraday's law of electromagnetic induction and explain the role of negative sign in its expression. (b) Explain, with an example, that…

Stating Faraday's law of electromagnetic Induction $\displaystyle 1$ Explaining the role of negative sign $\displaystyle 1$ (b)Explaining consistency of Lenz law with conservation of energy $\displaystyle 1$

The magnitude of induced emf in a circuit is equal to the time rate of change of magnetic flux.

\[\text { Mathematically, } \quad \mathrm{e}=-\mathrm{d} \Phi / \mathrm{dt} \]

Negative sign indicates that the direction of induced emf and hence induced current in closed loop opposes its cause.

When magnet is moved closer/away from the loop, same/ opposite pole is developed on the approaching face of the loop. So, mechanical work is required to move a magnet which gets