$A$ Carnot engine works first between $200^{\circ} C$ and $0^{\circ} C$ and then between $0^{\circ} C$ and $-200^{\circ} C$. The ratio of its efficiency in the two cases is

What is the efficiency of an ideal gas?

$A$ Carnot engine working between $400 \, K$ and $800 \, K$ has a work output of $1200 \, J$ per cycle. What is the amount of heat energy supplied to the engine from the source per cycle in $J$?

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 $27 \%$

In the $1^{\text{st}}$ case,a Carnot engine operates between temperatures $300 \, K$ and $100 \, K$. In the $2^{\text{nd}}$ case,as shown in the figure,a combination of two engines is used. The efficiency of this combination (in the $2^{\text{nd}}$ case) will be:

$A$ Carnot cycle operating between $T_H = 600 \ K$ and $T_C = 300 \ K$ produces $1.5 \ kJ$ of mechanical work per cycle. The heat transferred to the engine by the reservoir is: (in $kJ$)