An engine with an input temperature of 755K and an exhaust temperature of 453K has the same efficiency as an engine that is 40% efficient. Is this true or false? I am having trouble
Efficiency is usually defined as a benefit divided by a cost. Or in terms of temperature:
e=1−T cold/T hotAnswer:
True
Explanation:
The efficiency of a heat engine is defined as the ratio of work done by the energy to the input energy.
It is given by
\(\eta = \frac{W}{Q_{1}}\)
Where, W is the work done and Q1 is the input heat.
\(\eta = 1-\frac{T_{2}}{T_{1}}\)
Where, T2 is the temperature of cold reservoir and T1 is the temperature of hot reservoir.
Here, T1 = 755 K and T2 = 453 K
So, efficiency = \(\eta =1-\frac{453}{755}\)
efficiency = 40 %
So, it is true.