Question

State faraday’s law of electromagnetic induction and Lenz’s law.

Answer 1

Hint:Faraday’s laws of electromagnetic Induction predicts how a magnetic field interacts with an electrical circuit and produces an electromagnetic force also known as induced EMF. This phenomenon is known as electromagnetic induction.

Lenz’s law on the other hand gives the direction of induced EMF with respect to the direction of current.
Both of these laws require change in the magnetic field.

Complete Step By Step Answer:
Faraday’s Law of electromagnetic Induction was the conclusion made by Faraday after performing a series of experiments. These conclusions are summed up as two laws.

First Law:
Faraday’s first law states that when magnetic flux linking a conductor or coil changes an EMF is induced in it. This induced Emf lasts as long as the change in flux linkages continues.
Mathematically, this law is expressed as:\[e \propto \dfrac{{N({\varphi _2} - {\phi _1})}}{t}\]

Where:
\[e = \] Induced Emf
\[N = \] No. of turns in the coil

\[\dfrac{{({\varphi _2} - {\phi _1})}}{t} = \] Rate of change of flux linkages.

Second Law:
Faraday’s second law states that the magnitude of induced Emf in a conductor is directly proportional to the rate of flux linkages.
Mathematically, this law is expressed as :

\[e = N\dfrac{{d\varphi }}{{dt}}\]
Where:
\[e = \] Induced Emf
\[N = \] No. of turns in the coil
\[\dfrac{{d\varphi }}{{dt}} = \] Rate of Change in flux
Lenz’s law, on the other hand, gives the direction of induced EMF.
It states that the induced current will flow in such a direction so as to oppose the cause that produces it.
Mathematically, we can say:

\[e = - N\dfrac{{d\varphi }}{{dt}}\]

Here, the negative sign is a result of Lenz’s law. This reminds us that the negative sign implies the direction of induced current and hence EMF is opposite to the direction of change in magnetic field.

Note:Lenz’s law is based on Conservation of energy, opposing force is exerted due to change in magnetic field which results in the induced EMF.
Faraday’s Law is very important in physics as it tells us that change in magnetic field can in turn flow current through the wire.