Physics Textbook/Lenz's Law
Lenz's law is use to find the direction of flow of current due to induced e.m.f
It states that"the direction of the current always opposes the cause which produces it."
Lenz's law is also used to explain the law of conservation of energy.
When a magnet moves towards and away from the coil induce an e.m.f in it by change the flux linked of magnet and feeble current flows in the coil. Due to this magnetic field is produced which opposes the approaching movement of magnet. In this a work is done. At last the amount of work done is converted into heat energy which recycles the lenz's law. Hence lenz's law is also called law of conservation of energy.