Question

A closed-loop of wire is being moved so that it remains in a uniform magnetic field. The current induced in the coil is?

Answer 1

From the concept when the loop remains in the magnetic field, there is no change in magnetic flux linked with the loop and so no current will be induced in it, but when the loop arises out of the magnetic field, the flux related to it becomes less and so there is a current that is induced to oppose the decrease in magnetic flux which means that It will make a magnetic field downwards, such that the direction of current will be clockwise.

Complete step by step solution:
The direction in which the induced EMF drives current around a wire loop can be found through the negative sign. However, it is usually easier to determine this direction with Lenz’s law, the current induced in the coil is because when the loop remains in the field the magnetic flux remains constant. If the field is uniform and the loop does not change its angle relative to the field vector (so the cosine of the magnetic induction vector B and the loop surface vector does not change then there is no current induced. The purpose is that the EMF that is induced around a closed loop is directly proportional to the change rate (time derivative) of the magnetic flux composed by the loop. This is induction. The flux will change if the field strength changes and also its angle of coincidence changes. If not, the flux remains the same and there is no EMF induced, thus no current in the loop.

Note: Lenz’s law can also be considered in terms of the conservation of energy. We can use Lenz’s law to determine the directions of induced magnetic fields, currents, and EMF’S. The direction of an induced EMF always opposes the change in magnetic flux that causes the EMF, a result known as Lenz’s law. Hence we can use Lenz’s law to determine the direction of induced EMF whenever a magnetic flux changes Use Faraday’s law with Lenz’s law to determine the induced EMF in a coil and a solenoid.