$A$ diatomic ideal gas is used as the working substance in a Carnot engine. During the adiabatic expansion process,if the volume of the gas increases from $V$ to $32V$,what is the efficiency of the engine?

The efficiency of an ideal heat engine working between the freezing point and boiling point of water is ........ $\%$

$A$ Carnot engine operates between $227^{\circ}C$ and $27^{\circ}C$. The efficiency of the engine will be:

$A$ heat engine operates between a cold reservoir at temperature $T_{2} = 400 \, K$ and a hot reservoir at temperature $T_{1}$. It takes $300 \, J$ of heat from the hot reservoir and delivers $240 \, J$ of heat to the cold reservoir in a cycle. The minimum temperature of the hot reservoir has to be $.... K$.

$A$ reversible engine converts one-sixth of the heat input into work. When the temperature of the sink is reduced by $62^\circ C$,the efficiency of the engine is doubled. The temperatures of the source and sink are:

Who first proposed (invented) the Carnot engine?