A solid spherical conductor $($radius $=2$mm$)$ has a uniform surface charge density. Point A is $5$mm from the center of the sphere, and point B is on the surface of the sphere. If the electric potential at point A is $41$V lower than at point B$,$ what is the net charge on the sphere?What is the magnitude of the magnetic dipole moment of the bar magnet? Assume the bar is suitably far from the compass to permit the approximation