Physics - Heat & Thermo Question with Solution | TestHub

A Carnot engine $(\mathrm{E})$ is working between two temperatures 473 K and 273 K . In a new system two engines - engine $E_1$ works between 473 K to 373 K and engine $E_2$ works between 373 K to 273 K . If ${\eta }_{12},{\eta }_1$ and ${\eta }_2$ are the efficiencies of the engines $E,E_1$ and $E_2$, respectively, then