The potential energy of a magnetic moment in an external magnetic field is given by U = –μ · B.

(a) Calculate the difference in energy between the two possible orientations of an electron in a magnetic field B = 0.600 T k.

(b) If these electrons are bombarded with photons of energy equal to this energy difference, “spin flip” transitions can be induced. Find the wavelength of the photons needed for such transitions. This phenomenon is called electron spin resonance.