MUTUAL INDUCTION
                       

The mutual induction is the principle of operation of many machines like transformer, Induction motor it can explained below

Mutual induction is the process of passing of magnetic field from one circuit to another i.e, in transformer from primary to secondary winding.

When we apply voltage to the primary winding of transformer. Basically winding means an inductor and it opposes sudden change in current so it open circuited then slowly increases the current through inductor reaches its maximum hence it's flux.

                                                   As the flux is directly proportional to the current through the winding i.e, inductor.

                    flux  =  M I --------(1)

The above equation came from " L= flux/I "

So as we dealing with mutual induction instead of self so we kept 'M' instead of  ' L ' . We get equation (1).

As we discussed above flux is proportional to the current. The proportionality is removed by the content  ' M ' . So we get equation (1).

On the other side when we kept an another circuit near the first circuit i.e, another inductor with one inductor. The flux from primary to secondary due to mutual induction principle as explained above.

As the inductor reaches its maximum value i.e, reaches its study state value then reaches its maximum flux as we discussed above.

The secondary flux will cause current through the secondary circuit after Faraday's Laws of Electro Magnetic Induction happened. That current magnitude depends on the induced emf in secondary circuit. 

As ' I ' is current through the primary circuit so flux in the secondary depends on the primary current ' I ' .

So as the current in the primary changes accordingly the flux in the secondary also changes linearly as there are directly proportional to each other.

Below graph shows current (I) VS flux in primary (phi)

Where " I " is the current in the primary winding and " flux " is the secondary flux.

                         

                              I VS flux