The expansion of an ideal gas of mass $m$ at a constant pressure $P$ is given by the straight line $B$ in the $V-T$ graph. Then the expansion of the same ideal gas of mass $2m$ at a pressure $2P$ is given by the straight line:

$A$ gas container $A$ is in thermal equilibrium with another gas of the same mass in container $B$. If we denote the corresponding pressures and volumes by the suffixes $A$ and $B$,then which of the following statements is most likely to be true?

At $N.T.P.$,$1 \text{ cm}^3$ of oxygen and $1 \text{ cm}^3$ of hydrogen are kept in different containers. Which will have a greater number of molecules?

Air is filled at $60^{\circ} C$ in a vessel of open mouth. The vessel is heated to a temperature $t^{\circ} C$ so that $\frac{1}{4}$th of the air escapes from the vessel. Assuming air as an ideal gas and the volume of the vessel remains constant, the value of '$t$' is: (in $^{\circ} C$)

The adjoining figure shows graphs of pressure and volume of a gas at two temperatures $T_1$ and $T_2$. Which of the following is correct?

Under constant temperature,the graph between $P$ and $1/V$ is: