Shows a wire of length l which can slide on a U- shaped rail of negligible resistance. The resistance of the wire is R. The wire is pulled ot the right with a constant speed v. Draw an equivalent circuit diagram representing the induced emf by a battery. Find the current in the wire usingj this diagram.

Explanation

The emf is induced due to the moving wire
The magnitude of theis emf is `epsilon = vBl`
As the wire moves towards right, the force vec qv X vecB on a positive charge acts in the upward direction in the figure
The positve terminal of the equivalent battery appears upwards
The resistance of the wire acts as the internal resistance of the equivalent battery
The equivalent circuit is drawn i fingure(38
W8b
) The current in the circuit is , from Ohm's law, ` i = (epsilon)/(R ) = (vBl)/(R )`
It is in the upward direction along the wire