Q 11-11-098JEE MainJEE Main 2023 (1 Feb, Shift 2)Medium
A Carnot engine operating between two reservoirs has efficiency $\dfrac13$. When the temperature of cold reservoir is raised by $x$, its efficiency decreases to $\dfrac16$. The value of $x$, if the temperature of hot reservoir is $99^\circ\text{C}$, will be
Answer: (D) $62\ \text{K}$
$T_1=372$ K. $T_2=\dfrac23\times372=248$ K; new $T_2=\dfrac56\times372=310$ K. $x=62$ K.
Solution by Sreeraj P, M.Sc Physics