If X stands for the magnelic susceptibility of a substance. `mu` for its magnetic permeability and to `mu_(0)` the perincability of free space, then

Options

A. for a paramagnetic substance `X gt 0, mu gt 0`
B. for a paramagnetic substance : `X gt 0, mu gt mu_(0)`
C. for a diamagnetic substance `X lt 0,mult0`
D. Tora ferromagnelic substance. `X lt 1,multmu_(0)`

Answer

B, D

Explanation

Magnetic susceptibility is given by,
`X = mu_(r) - 1`
and again we know that `mu_(r) = mu/mu_(0)`
For paramagnetic substance, `X gt 0`
`therefore mu_(r) gt 1 or mu gt mu_(0)`
For diamagnetic substance, `-1 le X le 0`
`therefore 0 le mu_(r) lt 1 or mu lt mu_(0)`
For ferromagnetic substance, `X gt gt 1`
`therefore mu gtgt mu_(0)`