Physics - Heat & Thermo Question with Solution | TestHub

In a two-stage reversible heat engine a quantity of heat ${\mathrm{Q}}_1$ is absorbed at a temperature ${\mathrm{T}}_1$, work ${\mathrm{W}}_1$ is done and a quantity of heat ${\mathrm{Q}}_2$ expelled at a lower temperature ${\mathrm{T}}_2$ by the first stage. The second stage absorbs the heat expelled by the first, does work ${\mathrm{W}}_2$ and expels a quantity of heat ${\mathrm{Q}}_3$ at a lower temperature ${\mathrm{T}}_3$. Calculate the efficiency of the combination engine.