Thermodynamics PYQ — Page 5

The given figure represents two isobaric processes for the same mass of an ideal gas, then 

A gas mixture consists of $8$ moles of argon and $6$ moles of oxygen at temperature $T$. Neglecting all vibrational modes, the total internal energy of the system is

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:

Two conductors have the same resistances at $0^{\circ}C$ but their temperature coefficients of resistance are ${\alpha }_{1}$ and ${\alpha }_{2}$. The respective temperature coefficients for their series and parallel combinations are :

A real gas within a closed chamber at $27^{\circ} \mathrm{C}$ undergoes the cyclic process as shown in figure. The gas obeys $P V^3=R T$ equation for the path $A$ to $B$. The net work done in the complete cycle is (assuming $R=8 \mathrm{~J} / \mathrm{mol} \mathrm{K}$ ): 

P-T diagram of an ideal gas having three different densities $\rho_1, \rho_2, \rho_3$ (in three different cases) is shown in the figure. Which of the following is correct : 

Given below are two statements : Statement (I) : The mean free path of gas molecules is inversely proportional to square of molecular diameter. Statement (II) : Average kinetic energy of gas molecules is directly proportional to absolute temperature of gas. In the light of the above statements, choose the correct answer from the options given below :

A sample contains mixture of helium and oxygen gas. The ratio of root mean square speed of helium and oxygen in the sample, is:

If $\mathrm{n}$ is the number density and $\mathrm{d}$ is the diameter of the molecule, then the average distance covered by a molecule between two successive collisions (i.e. mean free path) is represented by :

If the collision frequency of hydrogen molecules in a closed chamber at $27^{\circ} \mathrm{C}$ is $\mathrm{Z}$, then the collision frequency of the same system at $127^{\circ} \mathrm{C}$ is :

A total of $48 \mathrm{~J}$ heat is given to one mole of helium kept in a cylinder. The temperature of helium increases by $2^{\circ} \mathrm{C}$. The work done by the gas is: Given, $\mathrm{R}=8.3 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$.

An ideal gas undergoes isothermal expansion at temperature T. If the volume doubles, by what factor does the pressure change?

The translational degrees of freedom $\left(f_t\right)$ and rotational degrees of freedom $\left(f_r\right)$ of $\mathrm{CH}_4$ molecule are:

A block of ice at $-10^{\circ}C$ is slowly heated and converted to steam at $100^{\circ}C$. Which of the following curves represent the phenomenon qualitatively:

A sample of 1 mole gas at temperature $\mathrm{T}$ is adiabatically expanded to double its volume. If adiabatic constant for the gas is $\gamma=\frac{3}{2}$, then the work done by the gas in the process is:

A thermodynamic system is taken from an original state $A$ to an intermediate state $B$ by a linear process as shown in the figure. Its volume is then reduced to the original value from $B$ to $C$ by an isobaric process. The total work done by the gas from $A$ to $B$ and $B$ to $C$ would be : 

The average kinetic energy of a monatomic molecule is $0.414\mathrm{eV}$ at temperature: (Use ${K}_{B}=1.38\times {10}^{-23}J{\mathrm{mol}}^{-1}{K}^{-1}$)

On celcius scale the temperature of body increases by $40^{\circ} \mathrm{C}$. The increase in temperature on Fahrenheit scale is :

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio of $\frac{{C}_{p}}{{C}_{v}}$ for the gas is :

The heat absorbed by a system in going through the given cyclic process is : 

$0.08\mathrm{kg}$ air is heated at constant volume through $5^{\circ}C$. The specific heat of air at constant volume is $0.17\mathrm{kcal}{\mathrm{kg}}^{-1}^{\circ}{C}^{-1}$ and $1J=4.18\mathrm{joule}{\mathrm{cal}}^{-1}$. The change in its internal energy is approximately.

Choose the correct statement for processes $A$ & $B$ shown in figure. 

The pressure and volume of an ideal gas are related as $P{V}^{\frac{3}{2}}=K$ (Constant). The work done when the gas is taken from state $A({P}_{1},{V}_{1},{T}_{1})$ to state $B({P}_{2},{V}_{2},{T}_{2})$ is :

Two moles of a monoatomic gas is mixed with six moles of a diatomic gas. The molar specific heat of the mixture at constant volume is :