Finally, I have found the explanation for the “One-way magnetic force” I found http://pengkuanem.blogspot.com/2013/10/one-way-magnetic-force.html. In fact it is the position of the test coil that prevents it to rotate. In Figure 1, I have drawn the test coil in a horizontal magnetic field B. The forces are acted on the coil’s horizontal side and are vertical.

Please read the article at
Not a “one-way” magnetic force http://pengkuanem.blogspot.com/2013/10/not-one-way-magnetic-force.html
or http://www.academia.edu/4838155/Not_a_one-way_magnetic_force

pdf or word

Here is a strange experiment. I made 2 magnets act a magnetic force on a current in the position shown in Figure 1. The 2 magnets stand vertically and generate the magnetic field B. The current I passes in a wire at some distance in front of them.

Please read the article at
One way magnetic force http://pengkuanem.blogspot.com/2013/10/one-way-magnetic-force.html
or
http://www.academia.edu/4777632/One_way_magnetic_force

One way magnetic force pdf or word