Which of the following diagrams (figure) depicts ideal gas behaviour?

1. (a), (c)
2. (a), (d)
3. (c), (d)
4. (a), (b)

A cylinder contains hydrogen gas at a pressure of \(249~\text{kPa}\) and temperature \(27^\circ~\mathrm{C}.\) Its density is: (\(R=8.3~\text{J mol}^{-1} \text {K}^{-1}\))
1. \(0.2~\text{kg/m}^{3}\)
2. \(0.1~\text{kg/m}^{3}\)
3. \(0.02~\text{kg/m}^{3}\)
4. \(0.5~\text{kg/m}^{3}\)

The process on an ideal gas as shown in the figure given below is:
             

1. isothermal
2. isobaric
3. isochoric
4. none of these

An ideal gas equation can be written as $\mathrm{P}=\frac{\mathrm{\rho RT}}{{\mathrm{M}}_0}$ where $\mathrm{\rho }$ and ${\mathrm{M}}_0$ are respectively: