A gaseous mixture enclosed in a vessel contains $1 \mathrm{g}$ mole of a gas $\mathrm{A}$ (with $\mathrm{\gamma }=5/3$ ) and another gas $\mathrm{B}$ (with $\mathrm{\gamma }=7/5$ ) at a temperature $\mathrm{T}$. The gases $\mathrm{A}$ and $\mathrm{B}$ do not react with each other and are assumed to be ideal. The number of gram moles of $\mathrm{B}$ if $\mathrm{\gamma }$ for the gaseous mixture is $19/13$ is:

Figure shows $P-T$ diagram for a given mass of an ideal gas for the process $A\to B.$ During this process, density of the gas is

Figure shows $V-T$ curves for a given mass of an ideal gas at pressures $P_1$ and $P_2.$ Then

The $P-V$ diagram of a gas at constant temperature are drawn. The curve $1$ is for a constant mass $m_1$ and temperature $T_1$ and curve $2$ is for a constant mass $m_2$ and temperature $T_2.$ Select the correct alternative.