If a source is at a temperature $T_1$ and a sink is at a temperature $T_2$,the efficiency of the Carnot engine is maximum when

An ideal gas heat engine operates in a Carnot cycle between $227^{\circ}C$ and $127^{\circ}C$. It absorbs $6\,kcal$ at the higher temperature. The amount of heat (in $kcal$) converted into work is equal to

What is a Carnot cycle?

The source temperature of a heat engine is $727^{\circ}C$ and the sink temperature is $227^{\circ}C$. What is the maximum possible efficiency of this engine?

Three Carnot engines operate in series between a heat source at temperature $T_1$ and a heat sink at a temperature $T_4$. There are two other reservoirs at temperatures $T_2$ and $T_3$. If the three engines are equally efficient,find the values of $T_2$ and $T_3$ in terms of $T_1$ and $T_4$,given that $T_1 > T_2 > T_3 > T_4$.

Explain heat engines and their working.