What is the magnitude of the minimum magnetic field needed to levitate the rod?
Hello Kyn, let us use the expression equating the magnetic Lorentz force against the weight of the rod. Magnetic Lorentz force = B i L Weight of the rod = Mg Just to levitate, BiL = Mg So B = Mg / iL B = 0.12*9.8 / 13*0.46 = 0.197 T The magnetic field of induction 0.197 T is to be applied along Z axis but inward.