A Carnot engine ( $E$ ) is working between two temperatures 473 K and 273 K . In a new system two en

Question

A Carnot engine ( $E$ ) 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\

Professor PC Thomas Classes · Answer

(a) : Efficiency of Carnot engine, $\eta=1-\frac{T_{2}}{T_{1}}$\ For Carnot engine $E, T_{1}=473 \mathrm{~K}$ and\ $T_{2}=273 \mathrm{~K}$\ $	herefore \quad \eta_{12}=1-\frac{273}{473}=\frac{200}{473}=0.42$\ or $\eta_{12}=42 \%$ $$ 	ext { or } 0.5=\frac{1200}{Q_{1}} \Rightarrow Q_{1}=2400 \mathrm{~J} $$