$A$ Carnot engine has the same efficiency between $800 \ K$ to $500 \ K$ and $x \ K$ to $600 \ K$. The value of $x$ is ...... $K$. (in $K$)

Give the basic features of a heat engine based on a cyclic process and obtain the formula for its efficiency.

What is the theoretical efficiency of a heat engine?

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

The temperature of the sink of a Carnot engine is $250 \ K$. In order to increase the efficiency of the Carnot engine from $25 \%$ to $50 \%$,the temperature of the sink should be increased by

$A$ Carnot engine,whose efficiency is $40\%$,takes in heat from a source maintained at a temperature of $500\ K$. It is desired to have an engine of efficiency $60\%$. Then,the intake temperature for the same exhaust (sink) temperature must be ....... $K$.