North pole of a bar magnet faces a closed ciruclar coil. It is oscillated rapidly along the common axis of the magnet and the coil. Determine the direction of induced current in the coil from Lenz's law.

Explanation

When the north pole of the bar magnet comes nearer the coil, then according to Lenz's law, the coil repels that pole. So, at the end of the coil facing the magnet, a north pole will be generated due to induced current. When viewed from the side of the magnet, this current will appear anticlockwise in direction. Conversely, when the magnet is taken away from the coil, the induced current at the same end will be clockwise in direction. If the magnet is oscillated periodically the induced current in the coil will also change direction periodically. Thus, an alternating current will be induced in the coil.