A paramagnetic substance has a magnetic susceptibility obeying the Curie law, x=C/T (C is const.), and an internal energy given by U=aT* (a is a positive const.). (i) Obtain the heat of magnetization when this material is kept at T, and the field is increased from 0 to H. (ii) If the field is reduced adiabatically from H, to zero, what will be the change in temperature? (Adiabatic demagnetization.)