Answer:
efficiency = 0.678
Explanation:
First we have to change temperatures from °C to K (always in thermodynamics absolute temperature is used).
[tex]\text{hot body temperature,}T_H = 1200 \circC + 273.15 = 1473.15 K[/tex]
[tex] \text{cold body temperature,} T_C = 200 \circC + 273.15 = 473.15 K[/tex]
Efficiency [tex] \eta [/tex] of a carnot engine can be calculated only with hot body and cold body temperature by
[tex] \eta = 1 - \frac{T_C}{T_H}[/tex]
[tex] \eta = 1 - \frac{473.15 K}{1473.15 K}[/tex]
[tex] \eta = 0.678[/tex]
