Magnetic Materials — Important Questions

Copper, Gold, Bismuth

Diamagnetic materials have negative susceptibility and are weakly repelled by magnets. Examples include copper, gold, bismuth, silver, and water. Iron and nickel are ferromagnetic materials.

They have large positive susceptibility, They exhibit domain structure, They lose ferromagnetism above Curie temperature

Ferromagnetic materials have χ >> 1, show domain structure due to exchange interaction, and become paramagnetic above Curie temperature. They are strongly attracted by magnets, not weakly.

e/2me

The gyromagnetic ratio is defined as the ratio of magnetic moment to angular momentum. For an orbital electron, this ratio is e/2me, where e is electronic charge and me is electron mass.

2.51 T

Given: H = 1000 A/m, χ = 2000. Using B = μ₀(1 + χ)H = μ₀μᵣH. Here μᵣ = 1 + χ = 2001. Therefore, B = 4π × 10⁻⁷ × 2001 × 1000 = 2.51 T