A gas mixture consists of $2$ moles of oxygen and $4$ moles argon at temperature $T$. Neglecting all vibrational modes, the total internal energy of the system is

A Carnot engine has an efficiency of $1/6$. When the temperature of the sink is reduced by $62\,^oC$, its efficiency is doubled. The temperatures of the source and the sink are, respectively

A carnot engine, having an efficiency of $\eta  = 1/10$ as heat engine, is used as a refrigetator. If the work done on the system is $10\,J$ , the amount of energy absorbed from the reservoir at lower temperature is .......... $\mathrm{J}$

If $\Delta U$ and $\Delta W$ represent the increase in internal energy and work done by the system respectively in a thermodynamic process, which of the following is true?

One mole of an ideal diatomic gas undergoes a transition from $A$ to $B$ along a path $AB$ as shown in the figure

The change in internal energy of the gas during the transition is

An ideal gas undergoes a thermodynamics cycle as shown in figure. Which of the following graphs represents the same cycle?