Answer:
The source temperature is 1248 R.
Explanation:
Second law efficiency of the engine is the ratio of actual efficiency to the maximum possible efficiency that is reversible efficiency.
Given:
Temperature of the heat sink is 520 R.
Second law efficiency is 60%.
Actual thermal efficiency is 35%.
Calculation:
Step1
Reversible efficiency is calculated as follows:
[tex]\eta_{II}=\frac{\eta_{a}}{\eta_{rev}}[/tex]
[tex]0.6=\frac{0.35}{\eta_{rev}}[/tex]
[tex]\eta_{rev}=0.5834[/tex]
Step2
Source temperature is calculated as follows:
[tex]\eta_{rev}=1-\frac{T_{L}}{T}[/tex]
[tex]\eta_{rev}=1-\frac{520}{T}[/tex]
[tex]0.5834=1-\frac{520}{T}[/tex]
T = 1248 R.
The heat engine is shown below:
Thus, the source temperature is 1248 R.
