The battery discussed in the previous question is suddenly disconnected. It a current induced in the A pivoted aluminium bar falls much more slowly through a small region containing a magnetic field than a similar bar of insulating material. loop? If yes, when does it start and when does it end?

When the battery is suddenly disconnected, a current induced in B due to a sudden change in the flux through it. But it is only induced for a moment when the current suddenly falls to zero. According to the Lenz's law, the direction of the induced current is such that it opposes the magnetic field that has induced it. So that the induced current is such that it increases the decrease magnetic field. Therefore, if the current in loop A is in a clockwise direction, then the induced current in loop B will also be the clockwise direction. Hence two loops will attract each other.


Conclusion: If two circular loops are placed coaxially. A battery is connected to one of the loops. After some time, the battery is disconnected then the loops will attract each other.


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