Forces on magnets in a uniform magnetic field

[Trak]

If you have uniform magnetic field, would something like a halbach array which has a non symmetrical magnetic field experience a net force? If not, is there any way to shield one side of a magnet so that it would experience a net force?

On a similar note, if you wound a wire around a sphere in such as way as that the loops all had a rotation around a single axis (if that makes sense), would the resulting magnetic field inside this sphere be circular? If so, wouldn't a permanent magnet places in this sphere, with it's magnetic field cutting across the field o the sphere, experience a torque that would cause it to rotate?

To clarify on the sphere, say you wrapped a loop of wire around a sphere, then you wrapped another loop, but rotated your second loop a given number of degrees from the first, and then repeated the process through to 360 degrees.

 

[rumborak]

If you have uniform magnetic field, would something like a halbach array which has a non symmetrical magnetic field experience a net force?

Unless I am mistaken, a completely uniform field, impossible as it is to create, would exert no force.

On a similar note, if you wound a wire around a sphere in such as way as that the loops all had a rotation around a single axis (if that makes sense), would the resulting magnetic field inside this sphere be circular? If so, wouldn't a permanent magnet places in this sphere, with it's magnetic field cutting across the field o the sphere, experience a torque that would cause it to rotate?

To clarify on the sphere, say you wrapped a loop of wire around a sphere, then you wrapped another loop, but rotated your second loop a given number of degrees from the first, and then repeated the process through to 360 degrees.

You can derive the resulting field easily, since you can just add the magnetic field of each coil (Superposition Principle). They would just counteract each other, probably resulting in little to no net field inside.

 

[Johnsmith5969]

The rotating pattern of permanent magnets can be continued indefinitely and have the same effect. The effect of this arrangement is roughly similar to many horseshoe magnets placed adjacent to each other, with similar poles touching.