A ball of positive charge rotates about a vertical axis (Fig. P20.61). (a) If the rotation is

Question:

A ball of positive charge rotates about a vertical axis (Fig. P20.61).
(a) If the rotation is clockwise as viewed from above, what is the direction of the ball’s magnetic moment?
(b) If the charge on the ball is negative, what is the direction of the magnetic moment?

+q Figure P20.61