Susceptibility comes from the word “susceptible” means the easily affected. As I have discussed earlier that lines of force are weakly attracted towards paramagnetic materials, when these materials are placed in external magnetic field. It means paramagnetic materials are weakly effected by the field. Therefore the susceptibility of diamagnetic materials is positive but small.
As we have discussed in the earlier articles, that relative permeability of diamagnetic materials is greater than 1 and also there is a relation between relative permeability (μr)and susceptibility (χ):
μr = 1 + χ
where is μr
or χ = μr – 1
and μr is greater than 1
therefore, χ is positive
Reference: This article is referred from my book “electrical engineering materials” having ISBN 978-81-272-5069-0. In case of any question, you can put your question in the comment section.