Thermal Physics - Fermi-Dirac Statistics

Questions 71-73

A system in thermal equilibrium at temperature T consists of a large number N₀ of subsystems, each of which can exist only in two states of energy E₁ and E₂, where . In the expressions that follow, k is the Boltzmann constant.

For a system at temperature T, the average number of subsystems in the state of energy E₁ is given by

A. 

B. 

C.

D.

E.

(GR9277 #71)

Solution:

For only 2 states of energy → Fermi-Dirac distribution

Number of states: 

Since , take E₂ = 2ϵ and E₁ = ϵ

For E₁ = ϵ, number of states:

Answer: B