The efficiency of a Carnot engine operating between temperatures $27^{\circ}C$ and $-123^{\circ}C$ is .... $\%$?

$A$ 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:

$A$ Carnot engine is made to work between $200\,^{\circ}C$ and $0\,^{\circ}C$ first and then between $0\,^{\circ}C$ and $-200\,^{\circ}C$. The ratio of efficiencies $\left( \frac{\eta_2}{\eta_1} \right)$ of the engine in the two cases is:

An ideal Carnot heat engine has an efficiency of $30\%$. It absorbs heat from a hot reservoir at $727^{\circ}C$. The temperature of the cold reservoir is .... $^{\circ}C$.

$A$ Carnot engine takes $5000 \, kcal$ of heat from a reservoir at $727 \, ^{\circ}C$ and gives heat to a sink at $127 \, ^{\circ}C$. The work done by the engine is $.......... \times 10^{6} \, J$.

An engine operating between the boiling and freezing points of water will have:
$1.$ Efficiency more than $27 \%$
$2.$ Efficiency less than the efficiency of a Carnot engine operating between the same two temperatures.
$3.$ Efficiency equal to $27 \%$
$4.$ Efficiency less than $27 \%$