Answer: 1273.
- A 600
- B 0.0017
- C 1.9
- D 1273
Correct answer: D. 1273
Explanation: Relative permeability μr = B/(μ0 H) = 2.4/(4π×10⁻⁷ × 1500) ≈ 2.4/(1.885×10⁻³) ≈ 1273, showing the material is strongly ferromagnetic.
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.