Given, magnetic susceptibility of para-magnet at T1=73°C is 0.0075 Let magnetic susceptibility at T2=−173°C be χ2 We know magnetic susceptibility is given by χ∝
1
T
Therefore,
χ1
χ2
=
T2
T1
⇒
0.0075
χ2
=
−173∘C
−73∘C
⇒
0.0075
χ2
=
(273−173)K
(273−73)K
⇒
0.0075
χ2
=
100
200
⇒
0.0075
χ2
=
1
2
⇒χ2=2×0.0075=0.0150
Therefore, magnetic susceptibility at −173 °C will be 0.0150.