A paramagnetic system in an uniform magnetic field $H$ is thermally insulated from the surroundings. It has an induced magnetization $M=$ $a H / T$ and a heat capacity $c_H=b / T^2$ at constant $H$, where $a$ and $b$ are constants and $T$ is the temperature. How will the temperature of the system change when $H$ is quasi-statically reduced to zero? In order to have the final temperature change by a factor of 2 from the initial temperature, how strong should be the initial $H$ ?