What is the source temperature of the Carnot engine required to get $70 \%$ efficiency (in $^{\circ}C$)? Given sink temperature $= 27^{\circ}C$.

$A$ 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:

An engine is supposed to operate between two reservoirs at temperatures $727^oC$ and $227^oC$. The maximum possible efficiency of such an engine is:

$A$ steam engine delivers $5.4 \times 10^{8} \;J$ of work per minute and receives $3.6 \times 10^{9} \;J$ of heat per minute from its boiler. What is the efficiency of the engine? How much heat is wasted per minute?

An ideal gas heat engine operates in a Carnot cycle between $227^{\circ}C$ and $127^{\circ}C$. It absorbs $6 \times 10^4 \text{ cal}$ of heat at the higher temperature. The amount of heat converted to work is ......... $\times 10^4 \text{ cal}$.

The ratio of the efficiencies of two Carnot engines $A$ and $B$ is $1.25$. The temperature difference between the source and the sink is the same in both engines. The ratio of the absolute temperatures of the sources of engines $A$ and $B$ is