The magnetic susceptibility of a paramagnetic material at − 73 ∘ C is 0.0075 , its value at − 173 ∘ C will be

Options

A. `0.0030`
B. `0.0075`
C. `0.0045`
D. `0.015`

Answer

D

Explanation

According to Curie's law , the magnetic susceptibility (X) of a paramagnetic substance is inversely proportional to absolute temperature T i.e ., `chi prop 1/T`
` :. (chi_(1))/(chi_(2)) = (T_(2))/(T_(1)) or chi_(2) = chi_(1) (T_(1))/(T_(2))`
Here,
`chi_(1) = 0.0075 `
`T_(1) = - 73^(@)C = (273 - 73) K = 200 K `
`T-(2) = - 173 ^(@)C = (273 - 173 ) K = 100 K `
` :. " " chi_(2) = (0.0075) ((200K)/(100 K)) = 0.015`