The graph for $y = 1 - e^{-x}$ is represented by (for $x > 0$):

Heat is supplied to a diatomic gas at constant pressure. The ratio of $\Delta Q : \Delta U : \Delta W$ is

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

Initial pressure and volume of a gas are $P$ and $V$ respectively. First,its volume is expanded to $4V$ by an isothermal process,and then its volume is reduced to $V$ by an adiabatic process. Find its final pressure if $\gamma = \frac{3}{2}$.

If a heat engine and a refrigerator are working between the same two temperatures $T_1$ and $T_2$ $(T_1 > T_2)$,then the ratio of the efficiency of the heat engine to the coefficient of performance of the refrigerator is:

The three processes in a thermodynamic cycle shown in the figure are: Process $1 \rightarrow 2$ is isothermal; Process $2 \rightarrow 3$ is isochoric (volume remains constant); Process $3 \rightarrow 1$ is adiabatic. The total work done by the ideal gas in this cycle is $10 \, J$. The internal energy decreases by $20 \, J$ in the isochoric process. The work done by the gas in the adiabatic process is $-20 \, J$. The heat added to the system in the isothermal process is .............. $J$.