Metallic(noferrmagnetic) and nometallic particles in a solid waste may be separted as follows. The wasts is allowed to slide down an inclin over permanent magnets. The metallic particles slow down as compared to the nonmetallic ones and hence are separted. Discuss the role of eddy currents in the process.

A metallic rod of mass per unit length 0.5kgm^(-1) is lying horizontally on a smooth inclined plane which makes an angle of 30^(@) with the horizontal. The rod is not allowed to slide down by flowing a current through it when a magnetic field of induction 0.25 T is acting on it in the vertical direction. The current flowing in the rod to keep it stationary is.