Consider a metallic pipe with an inner radius of 1 cm. If a cylindrical bar magnet of radius 0.8 cm is dropped through the pipe, it takes more time to come own than it takes for a similar unmagnetized cylindrical iron bar dropped through the metallic pipe. Explain.

Hint: The force on the coil is the result of the rate of change of magnetic flux.
Step 1: When a cylindrical bar magnet of radius 0.8 cm is dropped through the metallic pipe with an inner radius of 1 cm, flux linked with the cylinder changes consequent eddy currents are produced in the metallic pipe. According to Lenz's law, these currents will oppose the (cause) motion of the magnet.
Step 2: Therefore, the magnet's downward acceleration will be less than the acceleration due to gravity g. On the other hand, an unmagnetized iron bar will not produce eddy currents and will fall with an acceleration due to gravity g.
Thus, the magnet will take more time to come down than it takes for a similar unmagnetized cylindrical iron bar to drop through the metallic pipe.