Q. No. 2
(a) What are statistical ensembles? Describe in detail.
(b) Consider a system of four fixed particles, each having spin 1/2, so that each spin can point either up or down. Each particle has a magnetic moment along the z-axis of μ when it points up, and -μ when it points down. The system is placed in an external field H pointing along the z-axis. The magnetic quantum numbers are mi = ±1/2. Calculate the possible distribution of the particles, total magnetic moment, and total energy.
(c) In the previous example, describe the possible distribution of the particles when the total energy is equal to 3μH.