4 For each case shown below indicate the direction of the in

4

For each case shown below, indicate the direction of the induced current in the wire loop. A velocity vector drawn near the magnet indicates that the magnet is moving, and a velocity vector drawn near the loop indicates that the loop is moving.

Solution

Lenz\'s law states that the current induced in a circuit due to a change or a motion in a magnetic field is so directed as to oppose the change in flux and to exert a mechanical force opposing the motion.

using Lenz\'s law,

a) Counter-clock wise.

when magnet move towards a circular loop, it increases the flux through the loop direction of motion of magnet, to oppose this an emf induced in the loop produces the current in counter-clockwise direction. whereas the magnetic field induced by the current in the loop produces the flux opposing the increasing flux due to the motion of magnet.

b) Clockwise.

since magnet is moving away from the loop, it decreases the flux through the loop to oppose this emf induced in the loop produces the current clockwise direction to generate secondary magnetic field to produce flux in opposite of primary magnetic field( magnet field) .

C) Clockwise

Since in this case south pole is moving towrads the circular, it induce current in clockwiise direction( opposite of part \'a\')

d) Counter-clock wise

In this case circular coil is moving towards a North pole of magnet, it is similar to part \'a\' . same procedure applied here as in part a.

e) Clockwise

similar to part b.