METBD 330 Lecture Notes

EIT/FE Exam Thermodynamics Questions

1.  An ideal gas experiences a constant pressure process at 206.8 kPa with an increase in volume of 566 Liters.  What work is required to cause this volume change ?

  1. 91200 kJ
  2. 117 kJ
  3. 0.084 kJ
  4. 60 kJ
  5. 0.84 kJ

2.  A 57 Liter volume of AIR is compressed from 1 atmosphere to 1.60 atm. in an isentropic process.  What is the final volume of the air if it is further compressed to 208 kPa in an isentropic process ?

  1. 34 L
  2. 17 L
  3. 10.5 L
  4. 21 L
  5. 42 L

3.  How much energy is required to heat 2.5 kg of water from 70 C to 95 C at 100 kPa pressure ?

  1. 105 kJ
  2. 31 kJ
  3. 211 kJ
  4. 262 kJ
  5. 78 kJ

4.  A vapor and a liquid can coexist

  1. only at the triple point
  2. only above the critical pressure
  3. only below the triple point temperature
  4. only above the critical temperature
  5. below the critical temperature

5.  What is the enthalpy of water at 165 C with quality of 97% ?

  1. 4766 kJ/kg
  2. 3761 kJ/kg
  3. 2701 kJ/kg
  4. 2066 kJ/kg
  5. 2004 kJ/kg

6.  Air at 205 C and 345 kPa is compressed isothermally to one-tenth of its original volume.  What is the final pressure ?

  1. 690 kPa
  2. 6900 kPa
  3. 2585 kPa
  4. 34.5 kPa
  5. 3450 kPa

7.  Four kilograms of nitrogen gas is compressed in a reversible, adiabatic process from 101.325 kPa and 20 C to 506.625 kPa.  The compression process follows a polytropic relationship with n=1.4.  What work is done on the gas during the compression ?

  1. -885 kJ
  2. 508 kJ
  3. 776 kJ
  4. 885 kJ
  5. -508 kJ

8.  What is the efficiency of an ideal Carnot heat engine cycle operating between 38 C and 482 C ?

  1. 90 %
  2. 89 %
  3. 59 %
  4. 16 %
  5. 11 %

9.  A Carnot refrigeration cycle operates between -10 C and 23 C.  What is its coefficient of performance ?

  1. 1.3
  2. 3.7
  3. 4.5
  4. 7.9
  5. 8.9

10. A steam turbine receives 550 kPa steam with an enthalpy of 2955 kJ/kg.  The turbine exhausts to 175 kPa and the exhaust steam has an enthalpy of 2765 kJ/kg.  What is the energy used by the turbine ?

  1. 13132 kJ/kg
  2. 190 kJ/kg
  3. 263 kJ/kg
  4. 12890 kJ/kg
  5. none of the above

11.  Which of the following is an extensive property ?

  1. temperature
  2. weight
  3. composition
  4. pressure
  5. none of the above

12.  A 0.71 m3 tank contains 4.5 kg of an ideal gas.  The molecular weight of this gas is 44 kg/kmole and the gas temperature is 21oC.  What is the gas pressure ?

  1. 352 kPa
  2. 25 kPa
  3. 190 kPa
  4. 15497 kPa
  5. 25 MPa

13.  When the pressure of an ideal gas is doubled and the absolute temperature is halved, its volume is:

  1. constant
  2. doubled
  3. increased by 4 times
  4. cut in half
  5. one fourth of its original

14.  0.9 kg of hydrogen gas is cooled from 400oC to 350oC in an isometric process.  How much heat transfer occurs in this system ?

  1. 510 kJ
  2. -459 kJ
  3. -510 kJ
  4. 459 kJ
  5. none of the above

15.  An ideal gas in a frictionless, vertical piston-cylinder device is heated and expands from a volume of 0.04 m3 to 0.10 m3 while the pressure remains constant at 200 kPa.  What work is done by the system ?

  1. 8 kJ
  2. 10 kJ
  3. 12 kJ
  4. 14 kJ
  5. none of the above

 

Answers:  1) B,  2) A,  3) D,  4) E,  5) C,  6) E,   7) E,  8) C,  9) D,  10) B,  11) B  12) A,  13) E,  14) B, 15) C