The core of any transformer is laminated so as to

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $A$ bar magnet dropped through a metallic cylindrical pipe takes more time to come down compared to a non-magnetic bar with same geometry and mass.
Reason $R$: For the magnetic bar,Eddy currents are produced in the metallic pipe which oppose the motion of the magnetic bar.
In the light of the above statements,choose the correct answer from the options given below:

$A$ magnet is dropped down an infinitely long vertical copper tube.

What are eddy currents? Who discovered eddy currents?

$A$ light disc made of aluminium (a nonmagnetic material) is kept horizontally and is free to rotate about its axis as shown in the figure. $A$ strong magnet is held vertically at a point above the disc away from its axis. On revolving the magnet about the axis of the disc,the disc will (figure is schematic and not drawn to scale)-

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 down than it takes for a similar unmagnetised cylindrical iron bar dropped through the metallic pipe. Explain.