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

$A$ 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:

The efficiency of a heat engine that works between the temperatures where Celsius-Fahrenheit scales coincide and Kelvin-Fahrenheit scales coincide is (approximately) (in $\%$)

$A$ reversible Carnot heat engine converts $\frac{1}{4}$ of its input heat into work. When the temperature of the sink is reduced by $50 \ K$,its efficiency becomes $33 \frac{1}{3} \%$. The initial temperatures of the source and the sink respectively are

What is a heat engine?

The Carnot cycle is plotted on a $P-V$ graph. Which portion represents an isothermal expansion?