Answer: Roughly half of the original pole strength.
- A The same as the original pole strength
- B Roughly half of the original pole strength
- C Twice the original pole strength
- D One-fourth of the original pole strength
Correct answer: B. Roughly half of the original pole strength
Explanation: Cutting along the length divides the cross-sectional pole strength roughly in half while the length stays the same, so each piece ends up with about half the original pole strength.
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.