Lenz’s Law and Conservation of Energy
Lenz law is based on Faraday's law of induction, so before understanding Lenz's law; one should know what is Faraday’s law of induction? When a changing magnetic field is linked with a coil, an emf is induced in it. This change in magnetic field may be caused by changing the magnetic field strength by moving a magnet towards or away from the coil, or moving the coil into or out of the magnetic field as desired. Or in simple words, we can say that the magnitude of the emf induced in the circuit is proportional to the rate of change of flux.
Lenz's law states that when an emf is generated by a change in magnetic flux according to Faraday's Law, the polarity of the induced emf is such, that it produces an current that's magnetic field opposes the change which produces it.
The negative sign used in Faraday's law of electromagnetic induction, indicates that the induced emf (έ) and the change in magnetic flux (δ ΦB) have opposite signs.
Where έ = Induced emf δ ΦB= change in magnetic flux N = No of turns in coil
