Question
Asked Oct 9, 2019
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A heat engine operates with sink temperature 25° with the efficiency of 30%. By how
many kelvins should be raised for the source temperature to achieve an efficiency of 40%.
(а) 78 K
(b) 69 K
(c) 52 K
(d) 71 K
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A heat engine operates with sink temperature 25° with the efficiency of 30%. By how many kelvins should be raised for the source temperature to achieve an efficiency of 40%. (а) 78 K (b) 69 K (c) 52 K (d) 71 K

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Expert Answer

Step 1

Given, here Temperature of Heat sink is TC and initial and final efficiencies are denoted as η1 and η2 respectively

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T 25 °C 298.15 K n0.30 n=0.40

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Step 2

Now, the efficiency of heat engine is given by:

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Т. =1- Т. 298.15 K = 1- Т, T 425.92 K

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Step 3

For the final efficiency &eta...

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Т. n1- Т, 0.40 1-298.15 K Т. T496.91 K

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