Which of the following shows the correct relationship between the pressure $P$ and density $\rho$ of an ideal gas at constant temperature?

The figure shows graphs of pressure $(P)$ versus density $(\rho)$ for an ideal gas at two temperatures $T_1$ and $T_2$.

$A$ partition divides a container having insulated walls into two compartments $I$ and $II$. The same gas fills the two compartments. Based on the values given in the figure,the ratio of the number of molecules in compartments $I$ and $II$ is

At constant temperature, the pressure of a gas is decreased by $20 \%$. What is the percentage change in volume?

The equation of an ideal gas in terms of pressure $(P)$,absolute temperature $(T)$,and density $(d)$ is:

If the density of the Sun is $1.4 \, g \, cm^{-3}$, the pressure is $1.4 \times 10^9 \, \text{atm}$, and the molar mass of the gas in the Sun is $2 \, g \, mol^{-1}$, then the temperature of the Sun will be: [Take $R = 8.4 \, J \, mol^{-1} \, K^{-1}$]