State and prove the law of conservation of energy.

Explanation

The truth of Lenz.s law can be established on the basis of the law of conservation of energy. It can be explained as follaw: According to Lenz.s law, when a magnet is moved either towards or away from a coil, the induced current produced opposes its motion. Hence, there will always be a resisting force on the moving magnet . Work has to be done by some extralnal agency to move the magnet against this resisting force. Here the mechanical energy of the moving magnet is converted into Joule heat in the coil i.e., energy is converted from one from to another.
On the contrary to Lenz.s law, let us assume that the induced current helps the cause responsible for its production. Now when we push the magnet little bit towards the coil, the induced current helps the movement of the magnet towards the coil. Then the magnet starts moving towards the coil without any expense of energy. Then it becomes a prepetual motion machine. In practice, no such machine is possible. Hence, the assumption that the induced current helps the cause is wrong.