Share
A completely reversible heat engine operates with a source at 1500 R and a sink at 500 R. If the entropy of the sink increases by 10 Btu/R,
Question
A completely reversible heat engine operates with a source at 1500 R and a sink at 500 R. If the entropy of the sink increases by 10 Btu/R, how much will the entropy of the source decrease? How much heat, in Btu, is transferred from the source?
in progress
0
Physics
3 years
2021-07-27T11:12:03+00:00
2021-07-27T11:12:03+00:00 1 Answers
88 views
0
Answers ( )
Answer:
Explanation:
Efficiency of reversible engine
= (T₁ – T₂) / T₁ , T₁ and T₂ be temperature of source and sink respectively
= (1500 – 500 )R / 1500R
= 1000 / 1500
= 2 / 3
If Q₁ be heat extracted and Q₂ be heat dumped into sink
efficiency = (Q₁ – Q₂) / Q₁
given Q₂ / T₂ = 10
Q₂ = 10 T₂ = 10 x 500R = 5000BTu
Q₁ – 5000R / Q₁ = 2/3
3Q₁ – 15000R = 2Q₁
Q₁ = 15000BTu
Q₂ = 5000 BTu
Q₁ / T₁ = 15000R/ 1500R
= 10R
Decrease in entropy of source = 10R.
Heat transferred = Q₁ – Q₂
= 15000 – 5000 BTu
= 10000BTu
=