Four curves $A, B, C$ and $D$ are drawn in the adjoining figure for a given amount of gas. The curves which represent adiabatic and isothermal changes are

Adiabatic modulus of elasticity of a gas is $2.1 \times {10^5}N/{m^2}.$ What will be its isothermal modulus of elasticity $\left( {\frac{{{C_p}}}{{{C_v}}} = 1.4} \right)$

Starting with the same initial conditions, an ideal gas expands from volume $V_{1}$ to $V_{2}$ in three different ways. The work done by the gas is $W_{1}$ if the process is purely isothermal. $W _{2}$. if the process is purely adiabatic and $W _{3}$ if the process is purely isobaric. Then, choose the coned option

The volume of an ideal gas $(\gamma=1.5)$ is changed adiabatically from $5$ litres to $4$ litres. The ratio of initial pressure to final pressure is:

A sample of gas at temperature $\mathrm{T}$ is adiabatically expanded to double its volume. Adiabatic constant for the gas is $\gamma=3 / 2$. The work done by the gas in the process is : $(\mu=1 \mathrm{~mole})$