Magnetism: Same Pole Repulsion & Heteropolar Attraction

[Hir]

a negligible 12 nanoNewtons.

Confirm again, 12 nanonewtons is the attraction between the magnet and the earth's magnetic field?
A new question is added here, if the earth's magnetic induction increases by 10,000 times, find the attraction between the magnet and the earth's magnetic field at this time.

 

[hutchphd]

If nothing saturates ( probably true in this situation) then it will increase by ten thousand. We are assuming that you know how to turn up the Earth field.....an unlikely circumstance.

 

[berkeman]

This thread seems to have run its course, so it will be closed now.

Hir is correct that the magnetic force on a magnet is caused by the gradient of the magnetic field (its non-uniformity), and without a gradient you only get a torque (which is why compass needles align with the magnetic field).