La Crosse - Thermodynamics Exam 1 - practice

# La Crosse - Thermodynamics Exam 1 - practice -...

This preview shows pages 1–3. Sign up to view the full content.

Thermodynamics Exam 1 Practice Problems Dr Colton, Spring 2006 Sample Conceptual Questions (answer and explain): 1. Is it possible for two objects to be in thermal equilibrium if they are not in thermal contact with each other? 2. Chimneys are never used as a weight-bearing part of the structure of a building. Why? 3. Do the Celsius and Fahrenheit temperature scales ever read the same? 4. Explain why, when a thermometer is placed in hot water, the column of mercury first descends slightly and then rises. 5. The pendulum of a grandfather clock is made of brass. When the temperature increases, does the clock increase, decrease, or remain the same? 6. Why does a city have a higher temperature at night than does the surrounding countryside? 7. Do hotter objects always contain more heat than cooler objects? 8. If water is a poor thermal conductor, why can its temperature be raised quickly when it is placed over a flame? 9. Why can you grab a hot wooden object and not get burned, whereas if you grabbed a hot metal object at the same temperature it would burn you? 10. What does the ideal gas law predict about the volume of a sample of gas at absolute zero? Why is this prediction incorrect? 11. In which process is there a greater change in entropy, an isothermal or an adiabatic? 12. What is S for an irreversible change in which both endpoints coincidentally lie on an adiabat? 13. Electrical energy can be converted to heat energy with an efficiency of 100%, by sending a current through a resistor and using “Joule heating”: P = I 2 R. Explain how this doesn’t violate the 2 nd Law, which told us that the efficiency of an engine can never by 100%. 14. What is the State Postulate? 15. Consider an alcohol and a mercury thermometer that read exactly 0 ° C at the ice point and 100 ° C at the steam point. The distance between the two points is divided into 100 equal parts in both thermometers. Do you think they will give exactly the same reading at a temperature of, say, 60 ° C? Thermo Exam 1 Practice Problems – pg 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
16. What is the difference between intensive and extensive properties of a system. 17. Name several intensive properties. 18. A metal ball can pass through a metal ring. When the ball is heated, however, it gets stuck in the ring. What would happen if the ring, rather than the ball, were heated? 19. What would happen if you heated up a “bimetallic strip”? (That’s a long, narrow, piece of metal that is made up of two different metals joined back-to-back.) 20. Explain why the apparent expansion of a liquid in a glass bulb does not give the true expansion of the liquid. Would the apparent expansion be greater than or less than, the true expansion? 21. Give an example of a process in which no heat is transferred to or from a system, but the
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 9

La Crosse - Thermodynamics Exam 1 - practice -...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online