Question

Two circular loops are lying side-by-side horizontally on the surface of a table. A battery and switch are connected in series with the left-hand loop. When the switch is closed, a counterclockwise current begins to flow in the left-hand loop. What, if anything, happens in the right-hand loop due to the current flowing in the left-hand loop?

a) The current remains zero.

b) A counterclockwise current is induced.

c) A clockwise current is induced. Explain your answer.

Answer 1

Answer is Option (c)

Lenz's law states that the induced current flows in such a direction that the magnetic field associated to it tends to oppose the change that produces it.

The current in the left hand loop produces a positive flux. The magnetic field associated to it is along negative direction.

As a result, the right hand loop will have an increasing negative flux. The induced current opposes this by producing a magnetic field that is along the positive z direction.

So, a clockwise current is induced in the right hand loop.