Answer: parallel to.
- A parallel to
- B antiparallel to
- C perpendicular to
- D at 45° to
Correct answer: A. parallel to
Explanation: U = −mB cosθ is minimum (most negative) at θ = 0°, i.e. parallel alignment.
Magnetic field of a bar magnet: field lines emerge from the north pole and re-enter at the south pole outside the magnet, forming continuous closed loops. Image: Geek3, CC BY-SA 3.0, via Wikimedia Commons.
Concept context
Bar magnets, Earth's magnetism, and how different materials respond to an external magnetic field - diamagnetic, paramagnetic, and ferromagnetic behaviour.