In: Physics
Consider 2 two-state paramagnet systems, A and B, each containing 4 dipoles, in a magnetic field. The dipoles in System A are completely aligned, so N↑- N↓ =4. The dipoles in System 2 are completely random, N↑ = N↓. The two systems are brought together so that energy is exchanged between them. Energy conservation requires that the magnetic moment, and therefore the net spin, is unchanged, so that in equilibrium we have a system of eight dipoles with N↑ - N↓ =4.