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| 1 | |
At a pressure of 4 Mpa, the temperature at which liquid water boils is: |
| | A) | 29.0°C |
| | B) | 100.0°C |
| | C) | 143.6°C |
| | D) | 250.4°C |
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| 2 | |
Which state on this phase diagram is the critical state?
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| | A) | A |
| | B) | B |
| | C) | C |
| | D) | D |
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| 3 | |
In which region of the property diagram below are liquid-vapor mixture states located?
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| | A) | A |
| | B) | B |
| | C) | C |
| | D) | D |
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| 4 | |
The specific volume of a system consisting of refrigerant-134a at 1.0 Mpa is 0.01 m3/kg. The quality of the R-134a is: |
| | A) | 12.6 % |
| | B) | 47.2 % |
| | C) | 68.3 % |
| | D) | Not applicable |
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| 5 | |
A system contains water at 2.00 MPa, 220°C. The phase of this water is: |
| | A) | Liquid |
| | B) | Liquid-vapor mixture |
| | C) | Vapor |
| | D) | Solid |
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| 6 | |
A thermodynamic system contains water at 10 m3 of air whose pressure and temperature are 300 kPa, 127°C respectively. The weight fo this system is: |
| | A) | 93 N |
| | B) | 127 N |
| | C) | 192 N |
| | D) | 256 N |
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| 7 | |
Air in a closed piston-cylinder device arranged to maintain a pressure of 400 kPa is heated from 27°C to 227°C. Intially the volume of the air is 1 liter. What is the final air volume? |
| | A) | 0.5 liters |
| | B) | 0.00167 m3 |
| | C) | 2.4 liters |
| | D) | 0.036 m3 |
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| 8 | |
Propane gas (Pc = 4.26 MPa, Tc = 370 K) is maintained at 6.39 MPa and 444 K. How much volume does 1 kg of this gas fill? |
| | A) | 8.78 liters |
| | B) | 12.3 liters |
| | C) | 13.1 liters |
| | D) | 15.7 liters |
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| 9 | |
Steam at 1 MPa, 250°C is contained in a rigid vessel. It is now cooled to 25°C. The final quality (if applicable) of the vessel contents is: |
| | A) | 0.54 % |
| | B) | 2.63 % |
| | C) | 27.8 % |
| | D) | Not applicable |
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| 10 | |
R-134a flows in a pipe at a 30ºC with a specific volume of 0.04434 m3/kg. The internal energy and enthalpy of R-134a are 250.8 kJ/kg and 273.0 kJ/kg, respectively. The pressure of the refrigerant is |
| | A) | 0.5 MPa |
| | B) | 0.4 MPa |
| | C) | 0.3 MPa |
| | D) | 0.1 MPa |
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