Shows two long metal rails placed horizontally and parallel to each other at a separation i. A uniform magnetic field b exists in the vertically downward direction. A wire of mass m can slide on the rails. The rails are connected to a constant current source which drives a current I in the circuirt. The friction coefficient between the rails and the wire is `mu`. (a) What should be the minimum value of `mu` which can prevent the wire from sliding on the rails? (b) Describe the motion of the wire if the value of `mu` is half the value found in the previous part.