Thermodynamics Review Quiz 1. What is the difference between

Thermodynamics Review Quiz
Name:
1. What is the difference between internal energy and enthalpy. Why do we make the distinction?
2. An ideal gas expands from an initial temperature, pressure and volume to a final, fixed volume.
Which process provides the greater work - expanding at a constant pressure (isobaric) or at a
constant temperature (isothermal)? Explain your answer using a P -∀ diagram.
3. Explain the difference between a thermodynamic process and a thermodynamic cycle.
4. Under what conditions is the thermodynamic efficiency of a heat engine equal 100%?
5. The kinetic energy of a fluid increases as it is accelerated in an adiabatic nozzle. Where does
this increase in energy come from?
6. Consider the thermal energy generated by a television set. What would be a suitable choice
for a thermal reservoir in a thermodynamic analysis of the television set?
7. When can you use cv ∆T to represent the change in specific energy during a thermodynamic
process?
8. When can you use cp ∆T to represent the change in specific energy during a thermodynamic
process?
9. Does the work output of a steam turbine operating adiabatically have to be equal to the decrease
in energy of the steam expanding through it? Explain.
10. Does a heat engine that has an efficiency of 100% violate
the first law of thermodynamics
the second law of thermodynamics
both the first and second law of thermodynamics
none of the above
11. Is it possible to compress an ideal gas isothermally in an adiabatic piston-cylinder device?
Explain your answer.
12. For saturated Freon-12 expanding through a turbine, which of the following expressions is valid
for calculating the specific work? Circle all answers that apply. Explain your answer(s).
(a) cp (Tout − Tin )
(b) hout − hin
(c) v (Pout − Pin )
(d) qin − qout
13. For helium flowing through a compressor at 200 ◦ C, which of the following expressions is valid
for calculating the specific work [kW/kg] of the compressor? Circle all answers that apply.
Explain your answer(s).
(a) cp (Tout − Tin )
(b) hout − hin
(c) v (Pout − Pin )
(d) qin − qout
Principles of Energy Conversion
MEEM 4200/5290
Page 1 of 2
September 9, 2014
Thermodynamics Review Quiz
Name:
14. Which of the following expressions is valid for calculating the specific heat transfer [Btu/lbm]
to/from the air in a liquid-gas heat exchanger (car radiator)? Circle all answers that apply.
Explain your answer(s).
(a) cp (Tout − Tin )
(b) hout − hin
(c) v (Pout − Pin )
(d) qin − qout
15. Which of the following expressions is valid for calculating the specific heat transfer [kW/kg]
to/from the water in a liquid-gas heat exchanger (car radiator)? Circle all answers that apply.
Explain your answer(s).
(a) cp (Tout − Tin )
(b) hout − hin
(c) v (Pout − Pin )
(d) qin − qout
Principles of Energy Conversion
MEEM 4200/5290
Page 2 of 2
September 9, 2014

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