Magnetic Materials & Hysteresis

Dia, para, ferromagnetic.

Concept

Magnetic Materials & Hysteresis is a foundational idea in this chapter. The defining relationship is:

$\chi_{\rm dia} < 0, \quad \chi_{\rm para} > 0 \text{ small}, \quad \chi_{\rm ferro} \gg 1$

Curie's law: χ ∝ 1/T for paramagnets.

Worked Application

Apply the formula to a typical problem from your textbook. Identify the knowns, plug into the equation, and check that the units work out. Always sanity-check the magnitude before accepting an answer.

Common Confusions

• Confusing the variables in the formula — re-read the symbol definitions in the chapter.
• Forgetting unit conversions (cm vs m, g vs kg).
• Ignoring sign conventions where direction matters.

Key Takeaways

• Master the formula $\chi_{\rm dia} < 0, \quad \chi_{\rm para} > 0 \text{ small}, \quad \chi_{\rm ferro} \gg 1$ and one canonical example.
• See the chapter index for full derivations, traps and exam-grade problems.