Mag. force does not do any work, since force is perpendicular to displacement.
A rectangular loop of wire, supporting a mass m, hangs vertically with one end in a uniform magnetic field B, which points into the screen in the shaded region. If current increases continuously the mass will start rising up. Initial velocity is absolutely in the direction of force and hence the displacement. So how it's not doing any work?
Introduction to electrodynamics, Griffiths, Ex.5.3

Question

Mag. force does not do any work, since force is perpendicular to displacement.
 A rectangular loop of wire, supporting a mass m, hangs vertically with one end in a uniform magnetic field B, which points into the screen in the shaded region. If current increases continuously the mass will start rising up. Initial velocity is absolutely in the direction of force and hence the displacement. So how it's not doing any work?  
Introduction to electrodynamics, Griffiths,  Ex.5.3

anonymous · Answer

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