A heat engine has an efficiency of $\frac{1}{6}$. When the temeprature of sink is reduced by $62^{\circ} {C}$, its efficiency get doubled. The temeprature of the source is $.....^{\circ} {C}$

Six moles of an ideal gas performs a cycle shown in figure. If the temperature are $T_A = 600\,K,\,\,T_B = 800\,K,\,\,T_C = 2200\,K$ and $T_D = 1200\,K,$ the work done per cycle is...... $kJ$

Compressed air in the tube of a wheel of a cycle at normal temperature suddenly starts coming out from a puncture. The air inside

Gas obey $P^2V =$ constant. The initial temperature and volume are $T_0$ and $V_0$. If gas expands to volume $2V_0$, its final temperature becomes

$3\, moles$ of an ideal monoatomic gas perform a cycle as shown in the figure. The gas temperature in different states are: $T_1 = 400\, K$, $T_2 = 800\, K$, $T_3 = 2400\, K$ and $T_4 = 1200\,K$. The work done by the gas during the cycle is ...... $kJ$

$5.6\,liter$ of helium gas at $STP$ is adiabatically compressed to $0.7\,liter$ . Taking the initial temperature to be $T_1$ , the work done in the process is