A heat engine has a hot reservoir of 680°C and a cold reservoir of 220°C. What is the efficiency of the engine?
I do not know but I can tell you the MAXIMUM efficiency which is that of a Carnot cycle
High temp = 680 + 273 = 953 Kelvin
Low Temp = 220 + 273 = 493 Kelvin
Carnot efficiency = 100*(hot-cold)/hot
= 100 (953-493)/953
= 48.3 %
To calculate the efficiency of a heat engine, we need to use the formula:
Efficiency = 1 - (Tc/Th)
where Tc is the temperature of the cold reservoir and Th is the temperature of the hot reservoir.
Given that the hot reservoir has a temperature of 680°C and the cold reservoir has a temperature of 220°C, we can substitute these values into the formula:
Efficiency = 1 - (220/680)
Efficiency = 1 - 0.3235
Efficiency ≈ 0.6765
Therefore, the efficiency of the heat engine is approximately 0.6765 or 67.65%.