A bar magnet is freely falling along the axis of a circular loop as shown in figure. State whether its acceleration $a$ is equal to, greater than or less than the acceleration due to gravity $g$.

$a<g$. Because according to Lenz's law, whatever may be the direction of induced current, it will oppose the cause.

Here, the cause is, the free fall of magnet and so the induced current will oppose ti and the acceleration of magnet will be less that the acceleration due to gravity $g$. This can also be explained in a different manner. When the magnet falls downwards with its north pole downwards.

The magnetic field lines passing through the coil in the downward direction increase. Sonce, the induced current opposes this, the upper side of the coil will become north pole, so that field lines of coil's magnetic field are upwards. Now, like poles repel each other. Hence, $a<g$