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 lines form closed loops: outside the bar magnet they run from the N pole to the S pole; inside, they continue from S back to N, so the lines never start or end anywhere.
Concept context
Bar magnets, Earth's magnetism, and how different materials respond to an external magnetic field - diamagnetic, paramagnetic, and ferromagnetic behaviour.