For some solid materials, each atom possesses a permanent dipole moment by

Question

Question

This question was previously asked in

UPSC ESE Electronics & Communication 2022 Official Paper

virtue of incomplete cancellation of electron spin and / or orbital magnetic moments
rotation and alignation with external field
the presence of external field
rotation in opposite direction with external field

Answer 1

Key Points

Paramagnetism:
- Some solid materials, each atom possesses a permanent dipole moment by
  virtue of incomplete cancellation of electron spin and/or orbital magnetic moments.
- In the absence of an external magnetic field, the orientations of these atomic magnetic
  moments are random, such that a piece of material possesses no net macroscopic
  magnetization.
- These atomic dipoles are free to rotate, and paramagnetism
  results when they preferentially align, by rotation, with an external field.

F2 Savita Engineering 14-11-22 D1

These magnetic dipoles are acted on individually with no mutual interaction between adjacent dipoles.
Inasmuch as the dipoles align with the external field, they enhance it, giving rise to a relative permeability μ_r that is greater than
unity, and to a relatively small but positive magnetic susceptibility.