Quiz

1.

Why there is no 1/N! factor in the grand partition function (2)?

$$\Xi = \sum_{\{\sigma\}} \exp\bigl(\beta\mu N_p-\beta E_p\bigr)$$

2.

Compressibility at the liquid-gas critical point tends to

(a)

(b)

$\mathit{const}$

(c)

$\infty$

3.

Describe the phases that are at equilibrium at T<T_c, H=0 in Ising model.

4.

Does Ising model obey Gibbs phase rule?