A cylindrical shaped magnet is hanging by a thread from the ceiling, with its no

Question

A cylindrical shaped magnet is hanging by a thread from the ceiling, with its north pole at the top and south pole at the bottom. A closed circular loop of copper wire is fixed about 1 cm directly below the magnet, with the plane of the loop horizontal, and the magnet pointing along the central axis of the coil. The radius of the magnet is smaller than the radius of the loop. Now the string is cut, allowing the magnet to drop through the coil. Describe, using the Faraday-Lenz law, what happens as the magnet drops, and answer the following questions:
1/ Does the magnet drop with acceleration g? Why
2/ Is there an induced current in the loop as the magnet approaches the loop? What is the direction of the current? Why? Note:

Explanation / Answer

1) NO, the increase in flux linked with the coil will increase as magnet moves forward, this shall induce a current in the coil which creates a magnetic field around it. This magnetic field will also act on the magnet along with earth's gravity.

2)Magnet is falling with its south pole towards coil, as seen from top, flux coming out of loop will inc. so by lorentz law, current induced will be clockwise, as seen from top.

3) Magnet north pole moving away, so flux entering the loop is decreasing, so as seen from bottom current induced is anti clockwise.

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