12.
Which of the following conditions should be satisfied by the temperature T of a system of N non-interacting particles occupying a volume V, for Bose-Einstein condensation to take place?
(where, m is the mass of each particle of the system, kB is the Boltzmann constant, h is the Planck's constant and $$\xi $$ is the well known zeta function.)

14.
The equation of state of a dilute gas at very high temperature is described by $$\frac{{pV}}{{{k_B}T}} \approx 1 + \frac{{B\left( T \right)}}{V},$$    where V is the volume per particle and B(T) is a negative quantity. One can conclude that this is a property of

16.
Which of the following relations between the particle number density n and temperature T must hold good for a gas consisting of non-interacting particles to be described by quantum statistics?

17.
In a first order phase transition, at the transition temperature, specific heat of the system

18.
A monatomic crystalline solid comprises of N atoms, out of which n atoms are in interstitial positions. If the available interstitial sites are N', then number of possible micro-states is

19.
The temperature of a cavity of fixed volume is doubled. Which of the following is true for the black-body radiation inside the cavity?

20.
A heat pump working on the Carnot cycle maintains the inside temperature of a house at 22°C by supplying 450 kJ/s. If the outside temperature is 0°C, the heat taken, in kJ/s, from the outside air is approximately