Chapter 21: Q. 3 (page 594)

A heat engine extracts $55 K J$ of heat from the hot reservoir each cycle and exhausts $40 K J$ of heat. What are (a) the thermal efficiency and (b) the work done per cycle?

Short Answer

Expert verified

(a) The thermal efficiency is 27 %

(b) The work done per cycle is $15 k J$ .

Step by step solution

Step : 1 Introduction (part a)

(a) The ratio of work done per cycle to amount of heat retrieved from the warm reservoir $Q_{1}$ is the efficiency of the engine. The difference between the extracted heat and the work done per cycle equals the work done per cycle. $Q_{1}$ and exhausted heat $Q_{2}$ so we have

localid="1649241559768" $η = \frac{W}{Q_{1}}$

work done W per cycle is the difference of heat extracted and heat dumped into cold reservoir .

$W = 55 k J - 40 k J . = 15 k J .$

Substitute 15 kJ for W and 55 kJ for $Q_{1}$ in the equation of efficiency above.

$η = \frac{15 k J}{55 k J} \times 100 = 27 %$

Q_{1}

Step :2 Explanation (part b)

(b) The work done per cycle, as explained is difference of heat extracted and heat dumped into cold reservoir.

$W = Q_{1} - Q_{2}$

localid="1649242118588" $= 55 k J - 40 k J = 15 k J$

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A heat engine extracts $55 K J$ of heat from the hot reservoir each cycle and exhausts $40 K J$ of heat. What are (a) the thermal efficiency and (b) the work done per cycle?

Short Answer

Step by step solution

Step : 1 Introduction (part a)

Step :2 Explanation (part b)

One App. One Place for Learning.

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A heat engine extracts 55KJof heat from the hot reservoir each cycle and exhausts 40KJof heat. What are (a) the thermal efficiency and (b) the work done per cycle?

Short Answer

Step by step solution

Step : 1 Introduction (part a)

Step :2 Explanation (part b)

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Physics Textbooks

Thermodynamics

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Study anywhere. Anytime. Across all devices.

A heat engine extracts $55 K J$ of heat from the hot reservoir each cycle and exhausts $40 K J$ of heat. What are (a) the thermal efficiency and (b) the work done per cycle?