One ferromagnetic substance has magnetic susceptibility `chi_(m)` at `27^(@) C` temperature. At which temperature, it would become half ?

Options

A. `600^(@)C`
B. `300^(@) C`
C. `54^(@) C`
D. `327^(@) C`

Answer

D

Explanation

`chi_(m) prop (1)/( T)`
`therefore (chi_(m_(1) ) )/( chi_(m_(2)) ) = (T_(2) )/( T_(1))`
`(2 chi_(m_(1) ) )/(chi_(m_(1) ) ) = (T_2)/( 273+ 27) (because chi_(m_(2) ) = (chi_(m_(1 ) ))/( 2))`
`therefore T_(2) = 600 K`
`therefore t_(2) = T_(2) = 273 = 600 - 273 = 327 ^(@) C`