What is the efficiency of a Carnot engine working between the boiling point and the freezing point of water (in $\%$)?

$A$ diatomic ideal gas is used in a Carnot engine as a working substance. If during the adiabatic expansion part of the cycle,the volume of the gas increases from $V$ to $32V$,the efficiency of the engine is:

In a Carnot engine,as the gas gives heat energy to the sink,the temperature of the sink

$A$ Carnot engine has an efficiency of $50\%$ when its source is at a temperature $327^{\circ}C$. The temperature of the sink is $.........^{\circ}C$.

An ideal heat engine based on the Carnot cycle operates between temperatures of $227 \, ^\circ C$ and $127 \, ^\circ C$. If it absorbs $6 \times 10^{4} \, cal$ of heat from the high-temperature reservoir,the net work done by the engine is:

Three designs are proposed for an engine which is to operate between $500 \ K$ and $300 \ K$. Design $A$ claims to produce $150 \ J$ of work per $1000 \ J$ of heat input, design $B$ $450 \ J$ of work per $1000 \ J$, and design $C$ $300 \ J$ of work per $1000 \ J$. Which of the designs would you choose?