In this topic , Faraday’s Laws of Electromagnetic Induction has been described. Whenever electric current flows through a conductor, a magnetic field will set up in the space surrounding the conductor. So, we can say that when the electron is in motion, they produce a magnetic field. Alternatively, when a magnetic field cuts a conductor, it produces a flow of electrons in the conductor. The scientist, Mr. Michael Faradays, had invented the electricity by “converting magnetism” and he had formulated the basic laws of electromagnetic induction, upon Faraday’s Laws of Electromagnetic induction is based the operation of motors, generator, and transformer etc.
Now we describe how does “induced e.m.f” produce in a conductor?
Let, a stationary bar magnet is placed close to a insulated coil whose terminals are connected a sensitive Galvanometer
We can get the same result, when the bar magnet is stationary and conductor is suddenly away or towards the magnet. If a conductor AB laying within a magnetic field and a galvanometer is connected with that conductor which is shown in fig. It is found that whenever the conductor is moved up or down, a momentary deflection is produced in the galvanometer. It means that some e.m.f is induced in the conductor and the magnitude of e.m.f depends on the quickness of movement of conductor AB. It has been also observed that when the conductor AB is moved parallel to the direction of flux, so that it does not cut the flux. There will be no deflection in the galvanometer, that means there is no induced e.m.f in the coil.
From the above experiment, It has been concluded that whenever a conductor cuts or shears the magnetic flux, an e.m.f is always induced in the conductor and amount of e.m.f fully depends on the rate of cuts magnetic flux by the conductor , but not depends on the strength of magnetic flux.
Now, we describe the explanation of induced e.m.f in a coil. Let, N= No. of turns of a coil, Φ1= Initial value of magnetic flux which cuts the coil, Φ 2= Final value of flux in time t seconds. flux-linkages is meant the product of number of turns by flux linked with the coil, So, The initial flux linkages = N φ1 And final flux linkages = N φ2,
According to Faradays law of electromagnetic induction, the induced e.m.f is the rate of change of flux linkage.
Therefore, The induced e.m.f