If a wire is placed next to the face of a permanent magnet and a current sent through the wire, then a Lorentz force is present orthogonal to both the direction of the current and the magnetic field. I would assume there should be a linear force on the magnet in the other direction, but the magnetic field caused by the current in the wire should only create a torque on the magnet. So how is momentum conserved?
(Please refer to the attachment for figs.)
It is assumed that the current carrying conductor is placed close to a pole (say north pole) of a permanent bar magnet.
Force F on the current carrying conductor will act as shown in the above fig..
Force on the magnet will not act at a single point. It will be distributed along the magnet. Blue lines represent the magnetic lines due to the current carrying conductor. Obviously the magnetic flux density due to the current carrying conductor will be higher at the north pole (being nearer) than at the south pole. As such, the ...
Detailed explaination provided.