2. What is the difference between a perfect engine an ideal engine?

3. What is the difference between a real engine an ideal engine?

4. Please draw in the space provided an energy flow diagram for a perfect engine and for an ideal engine. Please fully label these diagrams. (looking for QH, QC and W as labels on these diagrams)

Perfect engine Ideal engine

5. Can you think of the name of one of two types of ideal engines covered in your lecture course ? (Carnot or Stirling)

6. Please draw in the space provided the PV diagram for the Stirling cycle. (they may need help)

Stirling cycle

7. From your energy flow diagram in question 4 for the ideal engine can you explain how the different parts relate to the PV diagram for the Stirling cycle in question 6? It may be easiest to label the PV diagram in question 6 with the labels from question 4.

8. What is the efficiency of an ideal engine? (looking for e = W/Q equation)

9. How might you improve the efficiency of an ideal engine? Redrawing the PV diagram in question 6 and modifying it may aid your explanation.

10. On your energy flow diagram and your PV diagram heatflows QH and QC are labelled. What relationship can your give between these two values? (students will probably respond with QH - QC = W)

11. Suppose you do not know the value of W, how would you then relate QH and QC? Consider the diagram in question 3 for the ideal engine.(if don't know go to next question)

12. The change in entropy for a system is the heat flow in or out of that system divided by the temperature of the system or [[Delta]]S = [[Delta]]Q/T. What can you say about the change in entropy for the Stirling cycle? (looking for QH /TH = QC /TC - if they are still stuck goto next question)

13a. What is the change in entropy of the hot source for the ideal engine in question 3 or question 6 ?

13b. What is the change in entropy of the cold sink for the ideal engine in question 3 or question 6 ?

13c. Can you relate these two values ?