A diatomic gas ($\gamma = 1.4$) at pressure 1 MPa and temperature 400 K undergoes adiabatic expansion. The new temperature is 320 K. Find the new pressure.

An experiment finds that when pressure changes by $\Delta P$ for a volume change $\Delta V$ = −V/100 adiabatically, the result gives $\Delta P / P = 1.4 / 100$. What gas type is this?

At the same temperature and pressure, 1 mole of $H_{2}$ and 1 mole of $O_{2}$ are mixed. The rms speed of $H_{2}$ is $v_H$ and of $O_{2}$ is $v_O$. Their average translational kinetic energies per molecule are:

**Assertion (A):** No heat engine can have efficiency greater than the Carnot efficiency operating between the same temperatures. **Reason (R):** Carnot engine is the most efficient because it uses an ideal gas as working substance.

1 mole of a monoatomic ideal gas at ($P_{1}$ = 10^{5} Pa, $V_{1}$ = 2 L, $T_{1}$ = 240 K) undergoes adiabatic expansion to $V_{2}$ = 16 L. Find $T_{2}$. ($\gamma = 5/3$)