Question

If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material is denoted by ${\mu }_d,{\mu }_p$ and ${\mu }_f$ respectively, then

• A. ${\mu }_d=0$ and ${\mu }_p\ne 0$
• B. ${\mu }_d\ne 0$ and ${\mu }_p=0$
• C. ${\mu }_p=0$ and ${\mu }_f\ne 0$
• D. ${\mu }_d\ne$ and ${\mu }_f\ne 0$

Answer 1

Answer: (A)

The magnetic dipole moment of a diamagnetic material is zero as each of its pair of electrons has opposite spins, i.e., ${\mu }_d=0.$ Paramagnetic substances have dipole moment > 0, i.e., ${\mu }_p\ne 0$ , because of the excess of electrons in its molecules spinning in the same direction.
Ferromagnetic substances are very strong magnets and they also have a permanent magnetic moment, i.e., ${\mu }_f\ne 0.$