A circular metal hoop is dropped over a bar magnet as sketched in Figure P21.26.
(a) Make a qualitative sketch of how the current induced in the hoop varies as a function of its height z. Start with the hoop well above the north pole of the magnet and let it fall all the way to large negative values of z(z <<-  L/2).
(b) Make a qualitative plot of the magnetic force on the hoop as a function of z. Interpret your result in terms of Lenz’s law.

 

z Metal hoop N- 2 Figure P21.26