Auniformly charged cylindrical shell of inside radius a, outside radius b (a ? b), and length l has a total charge q. the cylindrical shell spins with angular velocity w about its vertical axis. a) choosing a coordinate system with the origin at the center of the bottom surface of the cylinder and with the z-axis along the cylinder axis (so the bottom and top surfaces are at z 0 and l respectively), determine the volume current density within the cylindrical she b) determine the magnetic dipole moment of the shel. c) using the result of part b), find an approximate expression for the magnetic field produced by the shell at an arbitrary distant point, i. e., for r l and r > > b, where r is the distance to the point from the origin. express your result in spherical coordinates. i. e., in terms of r and ? (the angle to the observation point relative to the cylinder axis) d) what is the magnitude of the field determined in part c?