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प्रश्न
The susceptibility of a paramagnetic material is χ at 27° C. At what temperature its susceptibility be χ/3?
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उत्तर
Data: χm1 = χ, T1 = 27°C = 300 K, χm2 = `χ/3`
By Curie's law,
`"M"_"z" = "C" "B"_0/"T"`
Since Mz = χmH and B0 = μ0H
χmH = C`(mu_0"H")/"T"`
∴ χm = C `mu_0/"T"`
∴ χm ∝ `1/"T"`
∴ `(chi_"m1")/(chi_"m2") = "T"_2/"T"_1`
∴ `"T"_2 = (chi_"m1")/(chi_"m2") xx "T"_1 = 3 chi/chi xx 300 = 900 "K" = 627^circ "C"`
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