Thermodynamics

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TEST II 1.

EE Board September 2002 Which of the following is the Ideal gas law (equation)? A. B. C. D.

2.

EE Board September 1999 During adiabatic, internally reversible process, what is true about the change in entropy? A. B. C. D.

3.

It is temperature-dependent It is always greater than zero It is always zero It is always less than zero

EE Board October 1999 How does an adiabatic process compare to an isentropic process? A. B. C. D.

4.

V/T = k V = k 1/p P1/T1 = P2/T2 PV = n RT

adiabatic: heat transfer is not equal to zero; isentropic: heat transfer is zero. Both: heat transfer=0 ; isentropic : reversible adiabatic: heat transfer=0; isentropic: heat transfer is not equal to zero Both: heat transfer is not equal to zero; isentropic: irreversible

EE Board March 1998 Water boils when: A. B. C. D.

its saturated vapor pressure equals to the atmospheric pressure its vapor pressure equals 76 cm of mercury its temperature reaches 212 centigrade its vapor pressure is 1 gram per sq. cm

5.

EE Board March 1998 How many independent properties are required to completely fix the equilibrium state of a pure gaseous compound? A. B. C. D. 6.

EE Board March 1998 In an ideal gas mixture of constituents I and j, what is the mole fraction x, equal to? A. B. C. D.

7.

4 3 2 1

Pi/Pi + Pj PiVi/RT Ti/Ti + Tj Zi/Zi + Zj

EE Board March 1998 Which of the following is standard temperature and pressure (STP)?

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A. B. C. D.

0 degree Celsius and one atmosphere 32 degree Fahrenheit and zero pressure 0 degree Kelvin and one atmosphere 0 degree Fahrenheit and zero pressure

8.

EE Board April 1997 For heat engine operating between two temperatures (T2 > T1), what is the maximum efficiency attainable? A. B. C. D. 9.

EE Board April 1997 What is the value of work done for closed, reversible isometric system? A. B. C. D.

10.

1 – T1/T2 1 – T2/T1 T1 – T2 1 – T1 2/T2

zero positive negative positive or negative

EE Board April 1997 Which of the following statements is TRUE for an ideal gas, but not for a real gas? A. B. C.

PV = nRT An increase in temperature causes an increase in the kinetic energy of the gas The total volume of molecules on a gas is nearly the same as the volume of the gas as a

D.

No attractive force exists between the molecules of a gas

whole 11.

EE Board April 1996 The first law of thermodynamics is based on which of the following principles? A. B. C. D.

12.

Conservation of the mass Conservation of energy Action and reaction The entropy – temperature relationship

Which of the following cycle is used in vapor cycle power plant? A. B. C. D.

Brayton cycle Diesel cycle Ericson cycle Rankine cycle

13. Which ideal cycle below is based on the concept that the combustion process is both diesel and gasoline in the combustion of heat process that is constant pressure and constant volume? A.

Ericson cycle

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B. C. D. 14.

Which of the following is not a thermodynamic property? A. B. C. D.

15.

Dual cycle Brayton cycle Rankine cycle

Pressure Temperature Volume Phase

Which of the following compressibility factor of ideal gas?

A. 1 B. 2 C. 1.5 D. 0 16. The energy which includes all of the potential and kinetic energies of the atoms or molecules in a substance is known as ________. A. B. C. D.

internal energy enthalpy entropy total energy

17. What refers to the thermodynamic properties which are dependent on the amount of the substance present? A. B. C. D. 18.

Extensive properties Intensive properties Reversible properties Irreversible properties

What thermodynamic properties are independent of the amount of substance present? A. B. C. D.

Intensive properties Extensive properties Reversible properties Irreversible properties

19. What is known as the total heat and heat content at various times in the history? It also represents the useful energy of a substance. A. B. C. D.

Enthalpy Entropy Internal Energy Latent heat

20. What is the measure of the energy that is no longer available to perform useful work within the current environment? It is also known as the measure of the randomness of the molecules. A.

Entropy

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B. C. D. 21.

What is the temperature when water and vapor are in equilibrium with the atmospheric pressure? A. B. C. D.

22.

Ice point Steam point Critical point Freezing point

What is the unique state at which solid, liquid and gaseous phases can co-exist in equilibrium? A. B. C. D.

23.

Enthalpy Internal Energy Flow work

Triple point Critical point Boiling point Pour point

What refers to the state at which liquid and gaseous phases are indistinguishable? A. B. C. D.

Triple point Critical point Boiling point Pour point

24. What refers to the heat needed to change the temperature of the substance without changing its phase? A. B. C. D.

Latent heat Sensible heat Specific heat Entropy

25. What is defined as the quality of heat needed to raise the temperature of one kilogram of water by one degree Celsuis? A. B. C. D.

Kilojoule Btu Kilocalorie Latent heat

38. In the absence of any irreversibilities, a thermoelectric generator, a device that incorporates both thermal and electric effects, will have the efficiency of a/an __________. A. B. C. D. 39.

Carnot cycle Otto cycle Diesel cycle Rankine cycle

Which of the following best describe both Stirling and Ericson engines?

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A. B. C. D.

Internal combustion engines External combustion engines Carnot engines A vacuum

40. Nozzles do not involve any work interaction. The fluid through this device experiences which of the following? A. B. C. D.

No change in potential energy No change in kinetic energy No change in enthalpy A vacuum

41. The convergent section of a nozzle increases the velocity of the flow of the gas. What does it has to do on its pressure? A. B. C. D. 42.

At steam point, the temperatures of water and its vapor at standard pressure are: A. B. C. D.

43.

Pressure becomes constant Pressure equals the velocity It increases the pressure It decreases the pressure

extremes or maximum unity in equilibrium underfined

In a two-phase system, 30% moisture means A. B. C. D.

70% liquid and 30% vapor 70% vapor and 30% liquid 30% liquid and 100% vapor 30% vapor and 100% liquid

44. The thermal efficiency of gas-vapor cycle is ________ the thermal efficiency of a steam turbine or gas turbine A. B. C. D.

greater than less than not comparable equal

45. A property that indicates the natural direction of a process was first described by a German physicist. This property is called entropy. Who coined the word entropy? A. B. C. D.

Rudolf Clausius Lord Kelvin Gabriel Volks Rudolf Diesel

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46.

What is the temperature when water and vapor are in equilibrium with the atmospheric pressure? A. B. C. D.

Ice point Steam point Critical point Freezing point

47. When the expansion or compresison of gas takes place “without transfer of heat” to ot from the gas, the process is called: A. B. C. D.

reversible adiabatic polytropic isothermal

48. What refers to a liquid whose temperature is lower than the saturation temperature corresponding to the existing pressure? A. B. C. D.

Subcooled liquid Saturated liquid Pure liquid Compressed liquid

49. Which law that states “Entropy of all perfect crystalline solids is zero at absolute zero temperature”? A. B. C. D. 50.

What should be the temperature of both water and steam whenever they are present together? A. B. C. D.

51.

Zeroth law of thermodynamics First law of thermodynamics Second law of thermodynamics Third law of thermodynamics

Saturation temperature for the existing pressure Boiling point of water at 101.325 kPa Superheated temperature One hundred degrees centigrade

Which of the following occurs in a reversible polytropic process? A. B. C. D.

Enthalpy remains constant Internal energy does not change Some heat transfer occurs Entropy remains constant

52. The change that the system that undergoes from one equilibrium state to another is known as ______. A. B. C.

path process enthalpy change

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D.

entropy change

53.

What refers to the series of states through which a system passes during the process?

A. B. C. D.

path Quasi-static steps Reversibility moves Irreversibility moves

54.

The triple point of a substance is the temperature and pressure at which:

A. B. C. D.

the solid and liquid phases are in equilibrium the solid and gaseous phases are in equilibrium the solid, liquid and gaseous are in equilibrium the solid does not melt, the liquid does not boil and the gaseous does not condense

55.

Which of the following relations is not applicable in a free expansion process?

A. B. C. D.

Heat rejected is zero Work is done Change on temperature is zero Heat supplied is zero

56. the

What system in which neither mass nor energy cross the boundaries and it is not influenced by surroundings?

A. B. C. D.

Closed system Open system Isolated system All of these

57.

Ericson cycle has:

A. B. C. D.

two isothermal and two constant pressure processes two isothermal and two constant volume precesses two isothermal and two constant entropy processes two adiabatic, one constant volume and constant pressure processes

58.

A Stirling cycle has:

A. B. C. D.

two adiabatic and two constant volume processes two adiabatic and two constant pressure processes two isothermal and two constant pressure processes two isothermal and two constant volume processes

59. . A. B. C. D.

What is referred to by control volume? An isolated system closed system fixed region in space reversible process only

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60.

Which of the following is used in thermal power plant?

A. B. C. D.

Brayton cycle Reversed Carnot cyclet Rankine cycle Otto cycle

61.

The elongation and compression of a helical spring is an example of which process?

A. B. C. D.

Irreversible process Reversible process Isothermal process Adiabatic process

62.

A Bell-Coleman cycle is a reversed of which of the following cycles?

A. B. C. D.

Stirling cycle Joule cycle Carnot cycle Otto cycle

63.

Brayton cycle has:

A. B. C. D.

two isentropic and two constant volume processes two isentropic and two constant pressure processes One constant pressure, one constant volume and two adiabatic processes two isothermal, one constant volume and one constant pressure processes

64.

Otto cycle consist of:

A. B. C. D.

two isentropic and two constant volume processes two isentropic and two constant pressure processes two adiabatic and two isothermal processes two isothermal and two constant volume processes

65. When a system deviates infinitesimally from equilibrium at every instant of its state, it is undergoing what process? A. B. C. D.

isobaric process quasi-static process isometric process cyclic process

66.

An ideal gas is compressed isothermally. The enthalpy change is:

A. B. C. D.

always negative always positive zero undefined

67.

The state of thermodynamic system is always defined by its:

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A. B. C. D.

absolute temperature process properties temperature and pressure

68.

Entropy is the measure of:

A. B. C. D.

the internal energy of a gas the heat capacity of a substance randomness or disorder the change enthalpy of a system

69. its

What system in which there is no exchange of matter with the surrounding or mass does not cross boundaries?

A. B. C. D.

open system closed system isolated system nonflow system

70. Which one of the choices below refers to a system that is completely impervious to its surrounding or neither mass nor energy cross its boundaries? A. B. C. D.

open system closed system isolated system nonflow system

71.

What refers to a system in which there is a flow of mass across its boundaries?

A. B. C. D.

open system closed system isolated system nonflow system

72. When two bodies, isolated from other environment, are in thermal equilibrium with a third body, the two are in thermal equilibrium with each other. What do you call this statement? A. B. C. D.

zeroth law of thermodynamics First law of thermodynamics Second law of thermodynamics Third law of thermodynamics

73. At equal volume, at the same temperature and pressure conditions, the gases contain the same number of molecules. This refers to which of the following laws? A. B. C. D.

Boyle's law Charle's law Dalton's law Avogadro's law

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74. In the polytropic process we have pv n = constant, if the value of n is infinitely large, the process is called: A. B. C. D.

constant volume process constant pressure process constant temperature process adiabatic process

75.

Which of the following cannot be a property of a gas?

A. B. C. D.

density pressure viscosity temperature

76.

During adiabatic process, which of the follwing is the change in entropy?

A. B. C. D.

zero greater than zero less than zero infinity

77.

Which of the following best describe an adiabatic process?

A. B. C. D.

the system does no worl nor is work done on it the temperature of the system remains constant the heat of the system is changing no heat enters or leaves the system

78.

Boiling occurs when the vapor pressure attains which of the following pressures?

A. B. C. D.

the gage pressure the critical pressure the ambient pressure one standard atmosphere

79. Which of the following systems where there is no transfer of matter across the boundary? This system consists a fixed amount of mass, and no mass can cross its boundary or no mass can enter or leave the system. A. B. C. D.

closed system open system isolated system all of these

80.

Which of the following values characterize the state of the system?

A. B. C. D.

cycle process property enthalpy

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81.

In a complete heat engine cycle, which of the following is the area enclosed by the PV-diagram?

A. B. C. D.

the work done by the ingine per cycle the heat transferred to the engine the enthalpy of the per cycle the volume exhaust gas per cycle

82.

Which of the follwing engines is the least efficient?

A. B. C. D.

gas turbine diesel engine carnot engine gasoline engine

83.

Which of the follwing engines is the most efficient?

A. B. C. D.

gas turbine diesel engine carnot engine gasoline engine

84.

Which of the following is the process that cannot be found in a Carnot engine cycle?

A. B. C. D.

isobaric expansion adiabatic compression adiabatic expansion isothermal expansion

85.

In any process, the maximum amount of heat that can be converted in to mechanical energy:

A. B. C. D.

depends only on the exhaust temperature depends on the intake and exhaust temperatures is always 100% depends on the involvement of kinetic and potential energy involved

86.

Who coined the word energy?

A. B. C. D.

James Joule Thomas Young Rodulf Diesel Lord Kelvin

87.

An ideal heat engine can be 100% efficient only and only if its exhaust temperature is:

A. B. C. D.

same as the input temperature greater than the input temperature less than the input temperature 0 K temperature

88. What is the most frequent term used in thermodynamic heat engines which indicate how well an energy conversion or transfer process is accomplished? ENCODED 2001 REVIEWER IN ESAS BY ROJAS

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A. B. C. D.

cycle efficiency heatting effect reversibility

89.

Which of the following diagrams was introduced by German scientist R. Mollier?

A. B. C. D.

enthalpy-entropy (h-s) diagram temperature-entropy (t-s) diagram pressure-volume (p-v) diagram pressure-enthalpy (p-h) diagram

90.

Which of the following laws of thermodynamics which leads to the definition of entropy?

A. B. C. D.

first law second law third law law of conservation of energy

91.

Which of the following is the other term used for enthalpy-entropy (h-s) diagram?

A. B. C. D.

enthalpy diagram mollier diagram steam diagram entropy chart

92.

Which of the following defines the work output for every heat engine?

A. B. C. D.

work output is a function of exhaust temperature only work output is a function of intake temperature only work output is the difference between its heat intake and heat exhaust work output is the difference in entropy always

93. Which of the following is the value of n ( from PV n = C ) for a perfect gas undergoing isothermal process? A. B. C. D.

0 1 infinity n>1

94.

What is used for predicting the behavior of non-ideal gas?

A. B. C. D.

compressibility factor expansivity factor emissivity factor vann-d' whal's factor

95. For any reversible thermodynamic process, which of the following statements is true regarding the change in entropy? A.

dS = dQ/T

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B. C. D.

dS = 0 dS < 0 dS > 0

96.

Which of the following processes where the equation dQ = Tds is applicable?

A. B. C. D.

irreversible isometric reversible isothermal

97.

Which of the following thermodynamic relations is not correct?

A. B. C. D.

Q=U+W Tds = dU + pdV dH = Tds + Vdp H = U – pV

98.

Which of the following thermodynamic devices operates the reverse of the heat engine?

A. B. C. D.

thermal pump thermal evaporator thermal condenser thermal equilibrat

99.

What is another term used for isometric processes?

A. B. C. D.

isochoric process iolytropic process isothermal process reversible process

100.

Which of the following engines was introduced by a German engineer, Nickolas Otto?

A. B. C. D.

gasoline engine diesel engine gas turbine thermal engine

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

D C B A C A A A A A B

KEY TO TEST II

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12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58.

D B D A A A A A A B A B B C B A D B A D A A C B C D A B A D C B A A B B A D D C B A D C C A D

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59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. 93. 94. 95. 96. 97. 98. 99. 100.

C C B B B A B C C C B C A A D A C A D C A C A D C A B B D B A B B C B A D C D A A A

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