In the arrangement shown in Fig. 3.77 it is possible to measure (by means of a balance) the force with which a paramagnetic ball of volume V = 41 mm3 is attrabted to a pole of the electromagnet net M. The magnetic induction at the axis of the pole shoe depends on the height x as B = B0 exp (€“ axe2), where Bo = 1.50 T, a = 100 m-2. Find:
(a) At what height Xm the ball experiences the maximum attraction;
(b) The magnetic susceptibility of the paramagnetic if the maximum attraction force equals F max = 160μN.

M