Question

What is the significance of Lenz's law?

Answer 1

We have studied about Lenz’s law in electromagnetic induction. This law states that the direction of the induced current is such that it opposes the change that causes it. It can be represented by the following equation;
$V = - \dfrac{{dN\Phi }}{{dt}}$
where $V,\dfrac{{d\Phi }}{{dt}}$ and $N$ are induced voltage, rate of change of flux and number of turns of coil respectively. We can say that this law is a consequence of the law of conservation of energy.

Complete step by step answer:
Lenz's law states that the direction of an induced E.M.F. will be such if it were to cause a current to flow during a conductor in an external circuit, then that current would generate a field that might oppose the change that created it.
Lenz’s law also can be considered in terms of conservation of energy. If pushing a magnet into a coil causes current, the energy there current must have come from somewhere. We pushed a magnet against a field and did work on the system, which showed up as current. If it weren't the case that the induced field opposes the change within the flux, the magnet would be pulled in to produce a current empty having done work. potential energy would be created, violating the conservation of energy.

Note:
With the help of this law we can determine the direction and the magnitude of induced current in the coil due to change of the magnetic flux. The negative sign in the equation of Lenz’s law signifies that the electric current flows in a direction that the current opposes the change that causes it.