What is the net force experienced by a bar magnet placed in a uniform

What is the net force experienced by a bar magnet placed in a uniform magnetic field?

Zero
Depends upon length of the magnet
Never zero
Depends upon temperature
This question was previously asked in
UPSC NDA-1 – 2018
A bar magnet has two poles, a North pole and a South pole. When placed in a uniform magnetic field, the field exerts a force on each pole. The force on the North pole is in the direction of the magnetic field, and the force on the South pole is equal in magnitude but in the opposite direction to the magnetic field. Since the field is uniform, the forces on the two poles are equal and opposite, resulting in a net force of zero on the magnet. Although there is no net force, there is usually a torque which tends to align the magnetic dipole moment of the bar magnet with the direction of the uniform magnetic field.
– A bar magnet is a magnetic dipole.
– In a uniform magnetic field, the force on the North pole is equal and opposite to the force on the South pole.
– The net force is the vector sum of the forces on the individual poles.
If the magnetic field were non-uniform, the forces on the two poles would not be equal and opposite, and there would be a non-zero net force on the magnet, in addition to the torque. This is why magnets are attracted to or repelled from other magnets or ferromagnetic materials where the field is non-uniform.
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