1. Dec 23, 2008

### paweld

I can't solve the following problem:
Paramagnetic is thermally insulated. Its magnetisation M depends on external magnetic field H and temperature T: $$M=\frac{a H}{T}$$, heat capacity at constant H is $$C_H=\frac{b}{T^2}$$ (a, b are constants). How will the temperature of the system change when H is quasi-statically reduced to 0. In order to have final temperature change by the factor of 2 from the initial temperature how strong should be the initial H.

I know that I should find $$\left(\frac{\partial T}{\partial H} \right)_S$$ but I have no idea how to do it.

Thanks for help,

Pawel