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

$A$ $20 \,cm$ long tube is closed at one end. It is held vertically,and its open end is dipped in water until only half of it is outside the water surface. Consequently,water rises in it by height $h$ as shown in the figure. The value of $h$ is closest to (assume that the temperature remains constant,$P_{\text{atm}} = 10^5 \,N/m^2$,density of water $\rho = 10^3 \,kg/m^3$,and acceleration due to gravity $g = 10 \,m/s^2$): (in $,cm$)

Equal masses of $N_2$ and $O_2$ gases are filled in containers $A$ and $B$ respectively. The volume of container $B$ is twice the volume of container $A$. What is the ratio of the pressure in container $A$ to that in container $B$?

Which quantity is constant for two gases of equal volume at the same pressure and temperature?

If the pressure of an ideal gas contained in a closed vessel is increased by $0.5\%,$ the increase in temperature is $2 \, K.$ The initial temperature of the gas is ...... $^\circ C$

The density of a gas at normal pressure and $27^{\circ}C$ temperature is $24$. Keeping the pressure constant,the density at $127^{\circ}C$ will be: