CHAPTER 1: THERMODYNAMICS

1. Enthalpy of an ideal gas is a function only of .

A. entropy

B. internal energy

C. temperature

D. pressure

Answer: C. temperature

2. Which of the following is the most efficient thermodynamic

cycle?

A. Brayton

B. Otto

C. Carnot

D. Diesel

Answer: C. Carnot
It represents an idealized heat engine that operates between two heat reservoirs.

3. What is the first law of Thermodynamics?

A. internal energy is due to molecular motions

B. entropy of the universe is increased by irreversible

processes

C. energy can neither be created nor destroyed

D. heat energy cannot be completely transformed into work

Answer: C. energy can neither be created nor destroyed

4. An ideal gas is compressed isothermally. What is the enthalpy

change?

A. always negative
 B. always positive

C. zero

D. undefined

Answer: C. zero

5. Name the process that has no heat transfer.

A. Isothermal

B. Isobaric

C. Polytropic

D. Adiabatic

Answer: D. Adiabatic

6. An ideal gas is compressed in a cylinder so well insulated

that there is essentially no heat transfer. The temperature of

the gas

A. decreases

B. increases

C. remains constant

D. is zero

Answer: B. increases

7. What is the SI unit of pressure?

A. 𝑘𝑔/𝑐𝑚²

B. 𝑑𝑦𝑛𝑒𝑠/𝑐𝑚²

C. Pascal

D. Psi

Answer: C. Pascal
8. The equation (C𝑝 = 𝐶𝑣 + R) applies to which of the following?

A. enthalpy

B. ideal gas

C. two phase states

D. all pure substances

Answer: B. ideal gas

The equation Cp=Cv+R is known as Mayer's relation and applies to ideal gases.

9. In the flow processes, neglecting kinetic and potential

energies, the integral of Vdp represents what?

A. heat transfer

B. flow energy

C. enthalpy change

D. shaft work

Answer: D. shaft work

10. Mechanical energy of pressure transformed into energy of

heat.

A. Kinetic energy

B. Enthalpy

C. Heat exchanger

D. Heat of compression

Answer: B. Enthalpy

11. The theory of changing heat into mechanical work.

A. Thermodynamics

B. Kinematics

C. Inertia
 D. Kinetics

Answer: A. Thermodynamics

12. Average pressure on a surface when a changing pressure

condition exist.

A. Back pressure

B. Partial pressure

C. Pressure drop

D. Mean effective pressure

Answer: D. Mean effective pressure

13. Which of the following cycles consists two isothermal and

two constant volume processes?

A. Diesel cycle

B. Ericson cycle

C. Stirling cycle

D. Otto cycle

Answer: C. Stirling cycle

The Stirling cycle is characterized by its two isothermal (constant temperature) and two isochoric
(constant volume) processes. Here’s a brief breakdown:

Isothermal Expansion: The gas is heated and expands at a constant temperature.

Isochoric Cooling: The gas is cooled at a constant volume, reducing its temperature.

Isothermal Compression: The gas is compressed at a constant temperature.

Isochoric Heating: The gas is heated at a constant volume, increasing its temperature.

14. A control volume refers to what?

A. A fixed region in space

B. A reversible process

C. An isolated system
 D. A specified mass

Answer: A. A fixed region in space

15. In the polytropic process, 𝑃𝑣𝑛=constant, if the value of

n is infinitely large, the process is

A. isobaric

B. isometric

C. isothermal

D. polytopic

Answer: B. isometric

16. If the temperature is held constant and the pressure is

increased beyond the saturation pressure, then the working

medium must be:

A. compressed liquid

B. subcooled liquid

C. saturated vapor

D. saturated liquid

Answer: A. compressed liquid

17. Is one whose temperature is below the saturation temperature

corresponding to its pressure

A. Superheated vapor

B. Wet Vapor

C. Subcooled liquid

D. Saturated liquid

Answer: C. Subcooled liquid

18. Number of molecules in a mole of any substance is constant

called .

A. Rankine constant

B. Avogadro’s number

C. Otto constant

D. Thomspon constant

Answer: B. Avogadro’s number

19. If the pressure of a gas is constant, the volume is directly

proportional to the absolute temperature.

A. Boyle’s law

B. Joule’s law

C. Charles’ law

D. Kelvin’s law

Answer: C. Charles’ law

20. The number of protons in the nucleus of an atom or the

number of electrons in the orbit of an atom.

A. Atomic volume

B. Atomic number

C. Atomic weight

D. Atomic mass

Answer: B. Atomic number

21. In a P-T diagram of a pure substance, the curve separating

the solid phase from the liquid phase is:

A. vaporization curve

B. fusion curve
 C. boiling point

D. sublimation point

Answer: B. fusion curve

22. A water temperature of 18°F in the water cooled condenser is

equivalent in °C to .

A. 7.78

B. 10

C. 263.56

D. -9.44

Answer: B. 10

23. The latent heat of vaporization in Joules per kg is equal to

A. 5.4x102

B. 4.13x103

C. 22.6x105

D. 3.35x105

Answer: C. 22.6x105

24. Form of energy associated with the kinetic energy of the

random motion of large number of molecules.

A. Internal energy

B. Kinetic energy

C. Heat of fusion

D. Heat

Answer: D. Heat

25. If the temperature is held constant and the pressure

increased beyond the saturation pressure, then, working medium

must be:

A. saturated vapor

B. compressed liquid

C. saturated liquid

D. subcooled liquid

Answer: B. compressed liquid

26. Is the condition of pressure and temperature at which liquid

and its vapor are indistinguishable.

A. Critical point

B. Dew point

C. Absolute humidity

D. Relative humidity

Answer: A. Critical point

27. When a substance in gaseous state is below the critical

temperature, it is called -.

A. vapor

B. cloud

C. moisture

D. steam

Answer: A. vapor

28. Superheated vapor behaves

A. just as gas

B. just as steam

C. just as ordinary vapor

D. approximately as a gas

Answer: D. approximately as a gas

29. Whic of the following provides the basis for measuring

thermodynamic property of temperature?

A. Zeroth law of thermodynamics

B. First law of thermodynamics

C. Second law of thermodynamics

D. Third law of thermodynamics

Answer: A. Zeroth law of thermodynamics

30. Which of the following is commonly used as liquid absorbent?

A. Silica gel

B. Activated alumina

C. Ethylene glycol

D. None of these

Answer: C. Ethylene glycol

31. Mechanism designed to lower the temperature of air passing

through it

A. air cooler

B. air defense

C. air spill over

D. air cycle

Answer: A. air cooler

32. A device for measuring the velocity of wind.

A. Aneroid barometer
 B. Anemometer

C. Anemoscope

D. Anemograph

Answer: B. Anemometer

33. Heat normally flowing from a high temperature body a low

temperature body wherein it is impossible convert heat without

other effects.

A. first law of thermodynamics

B. second law of thermodynamics

C. third law of thermodynamics

D. zeroth law of thermodynamics

Answer: B. second law of thermodynamics

34. The temperature at which its vapor pressure is equal to the

pressure exerted on the liquid.

A. Absolute humidity

B. Calorimetry

C. Boiling point

D. Thermal point

Answer: C. Boiling point

35. A nozzle is used to

A. increase velocity and decrease pressure

B. decrease velocity as well as pressure

C. increase velocity as well as pressure

D. decrease velocity and increase pressure

Answer: A. increase velocity and decrease pressure

36. The sum of the energies of all the molecules in a system

where energies appear in several complex form.

A. Kinetic energy

B. Potential energy

C. Internal energy

D. Frictional energy

Answer: C. Internal energy

37. The total energy in a compressible or incompressible fluid

flowing across any section in a pipeline is a function of

A. Pressure and velocity

B. Pressure, density and velocity

C. Pressure, density, velocity and viscosity

D. Flow energy, kinetic energy, height above datum and internal energy

Answer: D. Flow energy, kinetic energy, height above datum and

internal energy

38. The ratio of the density of a substance to the density of

some standard substance.

A. Relative density

B. Specific gravity

C. Specific density

D. Relative gravity

Answer: B. Specific gravity

39. Is one whose pressure is higher than the saturated pressure

corresponding to its temperature.

 A. Compressed liquid

B. Saturated liquid

C. Saturated vapor

D. Superheated vapor

Answer: A. Compressed liquid

40. The changing of solid directly to vapor without passing

through the liquid state is called

A. Evaporation

B. Vaporization

C. Sublimation

D. Condensation

Answer: C. Sublimation

41. Weight per unit volume is termed as .

A. specific gravity

B. density

C. weight density

D. specific volume

Answer: C. weight density

42. What is the SI unit of force?

A. Pound

B. Newton

C. Kilogram

D. Dyne

Answer: B. Newton
43. The volume of fluid passing a cross-section of steam in unit

time.

A. steady flow

B. uniform flow

C. discharge

D. continuous flow

Answer: C. discharge

44. What equation applies in the first law of thermodynamics for

an ideal gas in a reversible open steady-state system?

A. 𝑄 − 𝑊 = 𝑈2−𝑈1

B. 𝑄 + 𝑉𝑑𝑝 = 𝐻2−𝐻1

C. 𝑄 − 𝑉𝑑𝑝 = 𝑈2−𝑈1

D. 𝑄 − 𝑃𝑑𝑣 =

𝐻2−𝐻1 Answer: B. 𝑄 +

𝑉𝑑𝑝 = 𝐻2−𝐻1

45. A pressure of 1 millibar is equivalent to

A. 1000 𝑑𝑦𝑛𝑒𝑠/𝑐𝑚2

B. 1000 cm of Hg

C. 1000 psi

D. 1000 𝑘𝑔/𝑐𝑚2

Answer: A. 1000

𝑑𝑦𝑛𝑒𝑠/𝑐𝑚2

46. When a system deviates infinitesimally from equilibrium at

every instant of its state, it is undergoing:

A. Isobaric process

B. Quasi-static process
 C. Isometric process

D. Cyclic process

Answer: B. Quasi-static process

47. What is the force which tends to draw a body towards the

center about which it is rotating?

A. centrifugal force

B. centrifugal in motion

C. centrifugal advance

D. centripetal force

Answer: D. centripetal force

48. What is the process that has no heat transfer?

A. Reversible isometric

B. Isothermal

C. Polytropic

D. Adiabatic

Answer: D. Adiabatic

49. Which of the engine is used for fighter bombers?

A. Turbojet

B. Pulsejet

C. Rockets

D. Ramjets

Answer: A. Turbojet

50. Exhaust gases from an engine possess:

A. solar energy
 B. kinetic energy

C. chemical energy

D. stored energy

Answer: B. kinetic energy

51. At critical point the latent enthalpy of vaporization is

A. temperature dependent

B. zero

C. minimum

D. maximum

Answer: B. zero

52. What is the force which tends to draw a body towards the

center about which it is rotating?

A. Centrifugal force

B. Centrifugal in motion

C. Centrifugal advance

D. Centripetal force

Answer: D. Centripetal force

53. When a system deviates infinitesimally from equilibrium at

every instant of its state, it is undergoing

A. isobaric process

B. quasi-static process

C. isometric process

D. cyclic process

Answer: B. quasi-static process

54. A pressure of 1 millibar is equivalent to

A. 1000 𝑑𝑦𝑛𝑒𝑠/𝑐𝑚2

B. 1000 cm of Hg

C. 1000 psi

D. 1000 𝑘𝑔/𝑐𝑚2

Answer: A. 1000

𝑑𝑦𝑛𝑒𝑠/𝑐𝑚2

55. Work done per unit charge when charged is moved from one

point to another.

A. Equipotential surface

B. Potential at a point

C. Electrostatic point

D. Potential difference

Answer: B. Potential at a point

56. How many independent properties are required to completely

fix the equilibrium state of a pure gaseous compound?

A. 1

B. 2

C. 3

D. 4

Answer: B. 2

57. Which of the following relations defines enthalpy?

A. h = u + 𝑝/𝑇

B. h = u + pv

C. h = u + 𝑝/𝑣

D. h = pv + T
Answer: B. h = u + pv

58. Which of the following is true for water at a reference

temperature where enthalpy is zero?

A. Internal energy is negative

B. Entropy is non-zero

C. Specific volume is zero

D. Vapor pressure is zero

Answer: A. Internal energy is negative

59. On what plane is the Mollier diagram plotted?

A. p-V

B. p-T

C. h-s

D. h-u

Answer: C. h-s

60. The compressibility factor z, is used for predicting

behavior of non-ideal gases. How is compressibility factor

defined relative to an ideal gas? (subscript c refers to

critical value)

A. z = 𝑃/𝑃𝑐

B. z = 𝑃𝑉/𝑅𝑇

C. z = T / Tc

D. z = 𝑇/𝑇𝑐 𝑃𝑐/𝑃

Answer: B. z = 𝑃𝑉/𝑅𝑇

61. How is the quality x of a liquid vapor mixture defined?

 A. The fraction of the total volume that is saturated vapor

B. The fraction of the total volume that is saturated liquid

C. The fraction of the total mass that is saturated vapor

D. The fraction of the total mass that is saturated liquid

Answer: C. The fraction of the total mass that is saturated

vapor

62. What is the expression for heat of vaporization?

A. ℎ𝑔

B. ℎ𝑓

C. ℎ𝑔 - ℎ𝑓

D. ℎ𝑓 - ℎ𝑔

Answer: C. ℎ𝑔 - ℎ𝑓

63. What is the value of the work done for a closed, reversible,

isometric system?

A. Zero

B. Positive

C. Negative

D. Indeterminate

Answer: A. Zero

64. What is the equation for thw work done by a constant

temperature system?

A. W = Mrt ln (𝑉2-𝑉1)

B. W = Mr (𝑇2-𝑇1) ln (𝑉2/𝑉1)

C. MRT ln (𝑉2/𝑉1)
 D. RT ln (𝑉2/𝑉1)

Answer: C. MRT ln

(𝑉2/𝑉1)

65. What is true about the polytropic exponent n for perfect gas

undergoing an isobaric process?

A. n ˃ 0

B. n ˂ 0

C. n = ∞

D. n = 0

Answer: D. n = 0

66. How does an adiabatic process compare to isentropic process?

A. Adiabatic: Heat transfer=0, Isentropic: Heat transfer=0

B. Adiabatic: Heat transfer=0, Isentropic: Heat transfer=0

C. Adiabatic: Reversible, Isentropic: Heat transfer=0

D. Both: Heat transfer=0, Isentropic: Reversible

Answer: D. Both: Heat transfer=0, Isentropic: Reversible

67. During an adiabatic, internally reversible process,what is

true about the change in entropy?

A. It is always zero

B. It is always less than zero

C. It is always greater than zero

D. It is temperature dependent

Answer: A. It is always zero

68. For an irreversible process, what is true about change in

entropy of the system and the surroundings?

 A. ds = 𝑑𝑞/𝑑𝑡

B. ds = 0

C. ds ˃ 0

D. ds ˂ 0

Answer: C. ds ˃ 0

69. For which type of process does the equation Dq=Tds hold?

A. Irreversible

B. Reversible

C. Isobaric

D. Isothermal

Answer: B. Reversible

70. Which of the following is true for any process?

A. ∆S (surrounding) + ∆S (system) ˃ 0

B. ∆S (surrounding) + ∆S (system) ˂ 0

C. ∆S (surrounding) + ∆S (system) ≤ 0

D. ∆S (surrounding) + ∆S (system) ≥ 0

Answer: D. ∆S (surrounding) + ∆S (system) ≥

71. Which of the following thermodynamic cycle is the most

efficient?

A. Brayton

B. Rankine

C. Carnot

D. Otto

Answer: C. Carnot
72. The ideal reversible Carnot cycle involves four basic

processes. What type of processes are they?

A. All isothermal

B. All adiabatic

C. All isentropic

D. Two isothermal and two isentropic

Answer: D. Two isothermal and two isentropic

73. What is the temperature difference of the cycle if the

entropy difference is ∆S, and the work done is W?

A. W - ∆S

B. W / ∆S

C. ∆S / W

D. ∆S - W

Answer: B. W / ∆S

74. Which of the following is not an advantage of a superheated,

closed Rankine cycle over an open Rankine cycle?

A. Lower equipment cost

B. Increased efficiency

C. Increased turbine life

D. Increased boiler life

Answer: D. Increased boiler life

75. Which of the following statements regarding Rankine cycle is

not true?

A. Use of a condensable vapor in the cycle increases the

efficiency of the cycle

 B. The temperature at which energy is transferred to and from

the working liquid are less separated than in a Carnot cycle

C. Superheating increases the efficiency of a Rankine cycle

D. In practical terms, the susceptibility of the engine

materials to corrosion is not a key limitation on the operating

efficiency

Answer: D. In practical terms, the susceptibility of the engine

materials to corrosion is not a key limitation on the operating

efficiency

76. Which of the following is standard temperature and pressure

(STP) ?

A. 0 K and 1 atm pressure

B. 0 F and zero pressure

C. 32 F and zero pressure

D. 0°C and 1 atm pressure

Answer: D. 0°C and 1 atm pressure

77. A substance is oxidized when which of the following occurs?

A. It turns red

B. It loses electrons

C. It gives off heat

D. It absorbs energy

Answer: B. It loses electrons

78. Which of the following is not a unit of pressure?

A. Pa

B. 𝑘𝑔/𝑚−𝑠
 C. bars

D. 𝑘𝑔/𝑚2

Answer: B.

𝑘𝑔/𝑚−𝑠

79. Which of the following is the definition of Joule?

A. Newton meter

B. 𝑘𝑔*𝑚𝑠2

C. unit of power

D. rate of change of energy

Answer: A. Newton meter

80. Which of gthe following is the basis for Bernoulli’s for

fluid flow?

A. The principle of conservation of mass

B. The principle of conservation of energy

C. The continuity equation

D. Fourier’s law

Answer: B. The principle of conservation of energy

81. Equation of state for a single component can be any of

the following except:

A. the ideal gas law

B. any relationship interrelating 3 or more state functions

C. relationship mathematically interrelating thermodynamic

properties of the material

D. a mathematical expression defining a path between states

Answer: D. a mathematical expression defining a path between

states
82. The state of a thermodynamic system is always defined by

its:

A. absolute temperature

B. process

C. properties

D. temperature and pressure

Answer: C. properties

83. In any non quasi-static thermodynamic process, the overall

entropy of an isolated system will

A. increase and then decrease

B. decrease and then increase

C. increase only

D. decrease only

Answer: C. increase only

84. Entropy is the measure of :

A. the internal energy of gas

B. the heat capacity of a substance

C. randomness or disorder

D. the change of enthalpy of a system

Answer: C. randomness or disorder

85. Which of the following statements about entropy is false?

A. Entropy of a mixture is greater than that of components under

the same condition

B. An irreversible process increases entropy of the universe

 C. Net entropy change in any closed cycle is zero

D. Entropy of a crystal at 0°F is zero

Answer: D. Entropy of a crystal at 0°F is zero

86. Work or energy can be a function of all of the following

except:

A. force and distance

B. power and time

C. force and time

D. temperature and entropy

Answer: C. force and time

87. Energy changes are represented by all except one of the

following:

A. m𝐶𝑝dt

B. - ʃ VdP

C. Tds - PdV

D. 𝑑𝑄/𝑇

Answer: D.

𝑑𝑄/𝑇

88. U + Pv is a quantity called :

A. shaft work

B. entropy

C. enthalpy

D. internal energy

Answer: C. enthalpy

89. In flow processes, neglecting KE and PE changes, ʃvdP

represents which item below?

 A. Heat transfer

B. Shaft work

C. Enthalpy change

D. Closed system work

Answer: B. Shaft work

90. Power maybe expressed in units of

A. ft - lb

B. Kw - hr

C. Btu

D. 𝐵𝑡𝑢/ℎ𝑟

Answer: D.

𝐵𝑡𝑢/ℎ𝑟

91. Equilibrium condition exist in all except which of the

following?

A. In reversible processes

B. In processes where driving forces infinitesimals

C. In a steady state flow process

D. Where nothing can occur without an effect on the system’s

surroundings

Answer: C. In a steady state flow process

92. In a closed system (with a moving boundary), which of the

following represents work done during isothermal process?

A. W = 0

B. W = P(𝑉2-𝑉1)

C. W = 𝑃1𝑉1 ln 𝑉2𝑉1

D. W = 𝑃2𝑉2−𝑃1𝑉1/1−𝑛
Answer: C. W = 𝑃1𝑉1 ln 𝑉2𝑉1

93. A substance that exists, or is regarded as existing, as a

continuoum characterized by a low resistance to flow and the

tendency to assume the shape of its container.

A. Fluid

B. Atom

C. Molecule

D. Vapor

Answer: A. Fluid

94. A substance that is homogenous in composition and homogenous

and invariable in chemical aggregation.

A. Pure substance

B. Simple substance

C. Vapor

D. Water

Answer: A. Pure substance

95. A substance whose state is defined by variable intensive

thermodynamic properties.

A. Pure substance

B. Simple substance

C. Vapor

D. Water

Answer: B. Simple substance

96. A system in which there is no exchange of matter with the

surrounding or mass does not cross its boundaries.

A. Open system

B. Closed system

C. Isolated system

D. Nonflow system

Answer: B. Closed system

97. A system that is completely impervious to its surrounding or

neither mass nor energy cross its boundaries.

A. Open system

B. Closed system

C. Isolated system

D. Nonflow system

Answer: C. Isolated system

98. A system in which there is a flow of mass across boundaries.

A. Open system

B. Closed system

C. Isolated system

D. Steady flow system

Answer: A. Open system

99. The properties that are dependent upon the mass of the

system and the total values such as total volume and total

internal energy.

A. Intensive properties

B. Extensive properties

C. Specific properties
 D. State properties

Answer: B. Extensive properties

100. The properties that are independent of the mass of the

system such as temperature, pressure, density and voltage.

A. Intensive properties

B. Extensive properties

C. Specific properties

D. State properties

Answer: A. Intensive properties

101. The properties for a unit mass and are intensive by

definition such as specific volume.

A. Intensive properties

B. Extensive properties

C. Specific properties

D. Thermodynamic properties

Answer: C

102. The condition as identified through the properties of the

substance, generally defined by particular values of any two

independent properties.

A. State

B. Point

C. Process

D. Flow

Answer: A

103. The only base unit with a prefix kilo is

A. kilogram
B. kilometer

C. kilojoule

D. kilopascal

Answer: A

104. The force of gravity on the body.

A. Weight

B. Specific gravity

C. Attraction

D. Mass

Answer: A

105. The mass per unit volume of any substance.

A. Density

B. Specific volume

C. Specific weight

D. Mass

Answer: A

106. The force of gravity on unit volume is

A. density

B. specific volume

C. specific weight

D. specific gravity

Answer: C

107. The reciprocal of density is

A. specific volume

B. specific weight

C. specific gravity

D. specific heat

Answer: A
108. Avogadro’s number, a fundamental constant of nature, is the

number of molecules in a gram-mole. This constant is

A. 6.05222x1023

B. 6.02252x1023

C. 6.20522x1023

D. 6.50222x1023

Answer: B

109. The ratio of the gas constant to Avogadro’s number is

A. Maxwell’s constant

B. Boltzmann’s constant

C. Napier’s constant

D. Joule’s constant

Answer: B

110. The absolute zero on the Fahrenheit scale is at

A. -459.7 ℉

B. 459.7 ℉

C. -273.15 ℃

D. 273.15 ℃

Answer: A

111. Absolute temperature on the Fahrenheit scale are called:

A. degrees Rankine

B. degrees Kelvin

C. absolute Fahrenheit

D. absolute Celsius

Answer: A

112. The absolute zero on the Celsius scale is at

A. -459.7 ℉
B. 459.7 ℉

C. -273.15 ℃

D. 273.15 ℃

Answer: C

113. What is the absolute temperature in Celsius scale?

A. degrees Rankine

B. degrees Kelvin

C. absolute Fahrenheit

D. absolute Celsius

Answer: B

114. The Fahrenheit scale was introduced by Gabriel Fahrenheit

of Amsterdam, Holland in what year?

A. 1592

B. 1742

C. 1730

D. 1720

Answer: D

115. The centigrade scale was introduced by Anders Celsius in

what year?

A. 1592

B. 1742

C. 1730

D. 1720

Answer: B

116. The National Bureau of Standards uses, among others, the

liquid-vapor equilibrium of hydrogen at

A. -196℃
B. 196 ℃

C. 253 ℃

D. -253 ℃

Answer: D

117. The National Bureau of Standards uses, among others, the

liquid-vapor equilibrium of Nitrogen at

A. -196 ℃

B. 196 ℃

C. 253 ℃

D. -253 ℃

Answer: A

118. The liquid-vapor equilibrium of Oxygen is at what

temperature?

A. 197.82 ℃

B. -197.82 ℃

C. 182.97 ℃

D. -182.97 ℃

Answer: D

119. The solid-liquid equilibrium of mercury is at what

temperature?

A. 38.87 ℃

B. -38.87 ℃

C. 37.88 ℃

D. -37.88 ℃

120. The solid-liquid equilibrium of Tin is at what temperature?

A. -38.87 ℃
B. 38.87 ℃

C. 231.9 ℃

D. -231.9 ℃

Answer: C

121. The solid-liquid equilibrium of Zinc is at what

temperature?

A. 231.9 ℃

B. 419.505 ℃

C. 444.60 ℃

D. 630.5 ℃

Answer: B

122. The liquid-vapor equilibrium of Sulfur is at what

temperature?

A. 231.9 ℃

B. 419.505 ℃

C. 444.60 ℃

D. 630.5 ℃

Answer: C

123. The solid-liquid equilibrium of antimony is at what

temperature?

A. 630.5 ℃

B. 419.505 ℃

C. 444.60 ℃

D. 231.9 ℃

Answer: A

124. The solid-liquid equilibrium of silver is at what

temperature?

A. 630.5 ℃

B. 960.8 ℃

C. 1063 ℃

D. 1774 ℃

Answer: B

125. The solid-liquid equilibrium of Gold is at what

temperature?

A. 630.5 ℃

B. 960.8 ℃

C. 1063 ℃

D. 1774 ℃

Answer: C

126. The solid-liquid equilibrium of platinum is at what

temperature?

A. 630.5 ℃

B. 960.8 ℃

C. 1063 ℃

D. 1774 ℃

Answer: D

127. The solid-liquid equilibrium of Tungsten is at what

temperature?

A. 3730 ℃

B. 3370 ℃

C. 3073 ℃

D. 3037 ℃
Answer: B

128. The device that measures temperature by the electromotive

force.

A. thermometer

B. thermocouple

C. electro-thermometer

D. thermoseebeck

Answer: B

129. The Emf is a function of the temperature difference between

the junctions, a phenomenon called:

A. Seebeck effect

B. Stagnation effect

C. Primming

D. Electromotive force

Answer: A

130. The device that measure temperature by the electromotive

force called thermocouple was discovered by:

A. Galileo

B. Fahrenheit

C. Celsius

D. Seebeck

Answer: D

131. When two bodies, isolated from other environment, are in

thermal equilibrium with a third body, the two are in thermal

equilibrium with each other.

A. Zeroth law of thermodynamics

B. First law of thermodynamics

C. Second law of thermodynamics

D. Third law of thermodynamics

Answer: A

132. The total entropy of pure substance approaches zero as the

absolute thermodynamic temperature approaches zero.

A. Zeroth law of thermodynamics

B. First law of thermodynamics

C. Second law of thermodynamics

D. Third law of thermodynamics

Answer: D

133. If any one or more properties of a system change the system

is said to have undergone a .

A. cycle

B. process

C. flow

D. control

Answer: B

134. When a certain mass of fluid in a particular state passes

through a series of processes and returns to its initial state,

undergoes a:

A. revolution

B. rotation

C. process

D. cycle

Answer: D

135. The term given to the collection of matter under

consideration enclosed within a boundary.

A. System

B. Matter
C. Environment

D. Atoms

Answer: A

136. The region outside the boundary or the space and matter

external to a system:

A. Ex-system

B. Surrounding

C. Matter

D. Extension

Answer: B

137. The true pressure measured above a perfect vacuum.

A. Absolute pressure

B. Gage pressure

C. Atmospheric pressure

D. Vacuum pressure

Answer: A

138. The pressure measured from the level of atmospheric

pressure by most pressure recording instrument like pressure

gage and open-ended manometer.

A. Gage pressure

B. Atmospheric pressure

C. Barometric pressure

D. Absolute pressure

Answer: A

139. The pressure obtained from barometric reading.

A. Absolute pressure

B. Gage pressure

C. Atmospheric pressure
D. Vacuum pressure

Answer: C

140. It is a form of energy associated with the kinetic random

motion of large number of molecules.

A. Internal energy

B. Kinetic energy

C. Heat

D. Enthalpy

Answer: C

141. The heat needed to change the temperature of the body

without changing its phase.

A. Latent heat

B. Sensible heat

C. Specific heat

D. Heat transfer

Answer: B

142. The heat needed by the body to change its phase without

changing its temperature

A. Latent heat

B. Sensible heat

C. Specific heat

D. Heat transfer

Answer: A

143. The measure of the randomness of the molecules of a

substance.

A. Enthalpy

B. internal energy

C. Entropy
D. Heat

Answer: C

144. The heat energy transferred to a substance at a constant

pressure process is

A. enthalpy

B. heat

C. internal energy

D. entropy

Answer: A

145. It is the energy stored within the body.

A. Enthalpy

B. Heat

C. Internal energy

D. Entropy

Answer: C

146. A theoretically ideal gas which strictly follows Boyle’s

law and Charle’s law of gases.

A. Universal gas

B. Perfect gas

C. Combined gas

D. Imperfect gas

Answer: B

147. In a confined gas, if the absolute temperature is held

constant, the volume is inversely proportional to the absolute

pressure.

A. Boyle’s law

B. Charle’s las

C. Dalton’ law
D. Avogadro’s law

Answer: A

148. In a confined gas if the absolute pressure is held constant

the volume is directly proportional to the absolute temperature.

A. Boyle’s law

B. Charle’s las

C. Dalton’ law

D. Avogadro’s law

Answer: B

149. The pressure exerted in a vessel by a mixture of gases is

equal to the sum of the pressures that each separate gas would

exert if it alone occupied the whole volume of the vessel.

A. A. Boyle’s law

B. Charle’s las

C. Dalton’ law

D. Avogadro’s law

Answer: C

150. At equal volume, at the same temperature and pressure

conditions, the gases contain the same number of molecules.

A. A. Boyle’s law

B. Charle’s las

C. Dalton’ law

D. Avogadro’s law

Answer: D

151. A process in which the system departs from equilibrium

state only infinitesimally at every instant.

A. Reversible process

B. Irreversible constant
C. Cyclic process

D. Quasi-static process

Answer: D

152. A process which gives the same states/conditions after the

system undergoes a series of processes;

A. Reversible process

B. Irreversible constant

C. Cyclic process

D. Quasi-static process

153. A thermodynamic system that generally serves as a heat

source or heat sink for another system.

A. Combustion chamber

B. Heat reservoir

C. Heat engine

D. Stirling engine

Answer: B

154. A thermodynamic system that operates continuously with only

energy (heat and work) crossing its boundaries; its boundaries

are impervious to the flow of mass.

A. Heat engine

B. Steady flow work

C. Stirling engine

D. Ericsson engine

Answer: A

155. A surface that is impervious to heat is

A. isothermal surface

B. adiabatic surface

C. isochoric surface
D. isobaric surface

Answer: B

156. One of the consequences of Einstein’s theory of relativity

is that mass may be converted into energy and energy into mass,

the relation being given by the famous equation, 𝐸 = 𝑚𝑐2 .

What the value of the speed of light C?

A. 2.7797x1010cm⁄s

B. 2.9979x1010cm⁄s

C. 1.7797x1010cm⁄s

D. 2.9979x1010cm⁄s

Answer: B

157. In what polytropic process we have 𝑝𝑣𝑛=constant,the value

of n is infinitely large, the process is called:

A. constant volume process

B. constant pressure process

C. constant temperature process

D. adiabatic process

Answer: A

158. The thermodynamic cycle used in a thermal power plant is:

A. Ericsson

B. Brayton

C. Joule

D. Rankine

Answer: D

159. For the same heat input and same compression ratio:

A. both Otto cycle and Diesel cycle are equally efficient

B. Otto cycle is less efficient than diesel cycle

C. efficiency depends mainly on working substance

D. none of the above is correct

Answer: A

160. A heat exchange process where in the product of pressure

and volume remains constant called:

A. heat exchange process

B. isentropic process

C. throttling process

D. hyperbolic process

Answer: D

161. Which of the following provides the basis for measuring

thermodynamics property of temperature?

A. Zeroth law of thermodynamics

B. First law of thermodynamics

C. Second law of thermodynamics

D. Third law of thermodynamics

Answer: A

162. 1 watt…

A. 1 Nm/s

B. 1 Nm/min

C. 1Nm/hr

D. 1 kNm/hr

Answer: A

163. Under ideal conditions, isothermal, isobaric, isochoric and

adiabatic processes are:

A. dynamic processes

B. stable processes

C. quasi-static processes

D. static processes
Answer: C

164. Isentropic flow is

A. perfect gas flow

B. irreversible adiabatic flow

C. ideal flow

D. reversible adiabatic flow

Answer: D

165. Exhaust gases from an engine possess

A. solar energy

B. kinetic energy

C. chemical energy

D. stored energy

Answer: B

166. The extension and compression of a helical spring is an

example of what process?

A. isothermal cycle

B. thermodynamic process

C. adiabatic process

D. reversible process

Answer: D

167. At critical point the latent enthalpy of vaporization is

A. dependent on temperature

B. zero

C. minimum

D. maximum

Answer: B

168. Which of the following relations is not applicable in a

free expansion process?

A. Heat supplied is zero

B. Heat rejected is zero

C. Work done is zero

D. change in temperature is zero

Answer: D

169. The triple point of a substance is the temperature and

pressure at which:

A. the solid and the liquid phases are in equilibrium

B. the liquid and gaseous phases are in equilibrium

C. the solid, liquid and the gaseous phases are in

equilibrium

D. the solid does not melt, the liquid does not boil and

the gas does not condense

Answer: D

170. According to Celsius statement

A. Heat flows from hot substance to cold substance, unaided

B. Heat cannot flow from cold substance to hot substance

C. Heat can flow from cold substance to hot substance with

the aid of external work

D. A and C

Answer: D

171. A heat engine is supplied heat at rate of 30,000 J/s gives

an output of 9Kw. The thermal efficiency of the engine is

A. 30%

B. 43%

C. 50%
D. 55%

Answer: A

172. The RMS velocity of hydrogen gas at N>T>P> is approximately

A. 3838 m/s

B. 1839 m/s

C. 4839 m/s

D. 839 m/s

Answer: B

173. Which of the following cycles has two isothermal and two

constant volume processes?

A. Joule cycle

B. Diesel cycle

C. Ericsson cycle

D. Stirling cycle

Answer: D

174. “It is impossible to construct a heat engine that operates

in a cycle and receives a given quantity of heat from a high

temperature body and does an equal amount of work”. The above

statement is known as:

A. Gay Lussac’s law

B. Kinetic Theory

C. Kelvin-Planck’s law

D. Joule-Thomson’s law

Answer: C

175. For steam nozzle, which of the following ratios will have

the value less than unity?

A. (Pressure at inlet)/ (pressure at outlet)

B. Specific volume at inlet/ (Temperature of outlet)

C. Temperature of steam at inlet/ (Temperature of steam at

outlet)

D. None of the Above

Answer: B

176. A Bell-Coleman cycle is a reversed

A. Stirling cycle

B. Brayton cycle

C. Joule cycle

D. Carnot cycle

Answer: C

177. Ericson cycle consists of the following four processes:

A. two isothermal and two constant volume

B. two isothermal and two constant isentropic

C. two isothermal and two constant pressure

D. two adiabatic and two constant pressure

Answer: C

178. A steam nozzle changes

A. kinetic into heat energy

B. heat energy into potential energy

C. potential energy into heat energy

D. heat energy into kinetic energy

Answer: D

179. Which is not correct for calculating air standard

efficiency?

A. All processes are reversible

B. Specific heat remains unchanged at all temperatures

C. No account of the mechanism of heat transfer is

considered

D. Gases dissociate at higher temperature

Answer: D

180. According to Pettlier Thomson effect:

A. It is impossible to construct a heat engine that

operates in a cycle and receives a given quantity of heat from a

high temperature body and does an equal amount of work

B. It is impossible to construct a device that operates in

a cycle and produces no effect other than transfer of heat from

a cooler body to hotter body

C. When two dissimilar metals are heated at one end and

cooled at other, e.m.f. that is developed is proportional to

difference f temperatures at two ends

D. Work can’t be converted into heat

Answer: D

181. In actual gases the molecular collisions are:

A. plastic

B. elastic

C. inelastic

D. inplastic

Answer: C

182. The Beattie-Bridgeman equation of state is quite accurate

in cases of:

A. all pressures above atmospheric pressure

B. densities less than about 0.8 times the critical density

C. near critical temperature

D. none of the above

Answer: B
183. Which of the following statement about Van der Waals

equation is correct?

A. It is valid for all pressures and temperatures

B. It represents a straight line on PV versus V plot

C. It has three roots of identical value at the critical

point

D. the equation is valid for diatomic gases only

Answer: C

184. The Clapeyron’s equation is applicable to:

A. 1 system in equilibrium

B. a change of state

C. a change of state when two phases are in equilibrium

D. a change of state when water and water vapor are

involved

Answer: C

185. The vapo pressure is related to the enthalpy of

vaporization by the:

A. Clausius-Claypeyron’s equation

B. Dalton’s law

C. Raoult’s law

D. Maxwell’s equation

Answer: A

186. Solubility of a gas in a liquid at small concentration can

be represented by which law?

A. Henry’s law

B. Clausius-Claypeyron’s equation

C. Dalton’s law

D. Raoult’s law
Answer: A

187. A compound pressure gauge is used to measure:

A. complex pressures

B. variable pressures

C. average pressures

D. positive and negative pressures

Answer: D

188. Which of the engine is used for fighter bombers?

A. Turboprop

B. Turbojet

C. Ramjet

D. Pulsejet

Answer: B

189. Past Board Question

The thermal efficiency of gas-vapor cycle as compared to

steam turbine or gas turbine

A. greater than

B. less than

C. not comparable

D. equal

Answer: A

190. Past Board Question

The process in which heat energy is transferred to a

thermal energy storage device is known as:

A. adiabatic

B. regeneration

C. intercooling

D. heat transfer
Answer: B

191. Past Board Question

The absolute zero in Celsius scale is:

A. 100

B. 0

C. -273

D. 273

Answer: C

192. Past Board Question

What is the temperature when water and vapor are in

equilibrium with the atmospheric pressure?

A. Ice point

B. Steam point

C. Critical point

D. Freezing point

Answer: B

193. Past Board Question

The temperature of a pure substance at a temperature of

absolute zero is:

A. Unity

B. Zero

C. Infinity

D. 100

Answer: B

194. Past Board Question

When the number of reheat stages in a reheat cycle is

increased, the average temperature:

A. increases
B. decreases

C. is constant

D. is zero

Answer: A

195. Past Board Question

A temperature measurement in an ordinary thermometer which

has constant specific humidity.

A. Critical temperature

B. Dew point temperature

C. Dry bulb temperature

D. Wet bulb temperature

Answer: B

196. Past Board Question

In a closed vessel, when vaporization takes place the

temperature rises. Due to the rising temperature, the pressure

increases until an equilibrium is established between the

temperature and pressure. The temperature of equilibrium is

called:

A. Dew point

B. Ice point

C. Superheated temperature

D. Boiling point

Answer: D

197. Past Board Question

When hot soup was served in a cup during dinner an engineer

was so eager to drink it. Since it was hot, he added cubes of

ice to cool the soup and stirred it He noticed that the dew

starts to form on the outermost surface of the cup. What is this

temperature equal to?

A. superheated temperature

B. equal to zero

C. standard temperature

D. equal to air’s dew point temperature

Answer: D

198. Is a measure of the energy that is no longer available to

perform useful work within the current environment.

A. Absolute entropy

B. Absolute enthalpy

C. Fugacity

D. Molar value

Answer: A

199. A graph of enthalpy versus entropy for steam.

A. Mollier diagram

B. Moody diagram

C. Steam diagram

D. Maxwell diagram

Answer: A

200. The reaction of inertia in an accelerated body is called

A. kinetic reaction

B. Endothermic reaction

C. Kinematic reaction

D. Dynamic reaction

Answer: A

201. A Mollier chart of thermodynamic properties is shown in

which of the following diagrams?

A. T-S diagram
B. P-V diagram

C. h-S diagram

D. p-h diagram

Answer: C

202. The following are included in the first law of

thermodynamics for closed system EXCEPT:

A. heat transferred in and of the system

B. work done by or on the system

C. internal energy

D. kinetic energy

Answer: D

203. All processes below are irreversible except one. Which one?

A. Magnetization with hysteresis

B. Elastic tension and release of a steel bar

C. Inelastic deformation

D. Heat conduction

Answer: B

204. The combination of conditions that best describes a

thermodynamic process is given by which of the following?

I. Has successive states through which the system passes

II. When reversed leaves no change in the system

III. When reversed leaves no change in the system or the

surroundings

IV. States are passes through so quickly that the surroundings

do not change

A. I and II

B. I and III

C. I and IV
D. I only

Answer: D

205. The sum of the energies of all the molecules in a system

where energies appear in several complex forms is the:

A. Kinetic energy

B. Potential energy

C. Internal energy

D. Frictional energy

Answer: C

206. The Carnot refrigeration cycle includes all of the

following process except:

A. Isentropic expansion

B. Isothermal heating

C. Isenthalpic expansion

D. Isentropic expansion

Answer: C

207. The maximum possible work that can be obtained a cycle

operating between two reservoirs is found from:

A. Process irreversibility

B. Availability

C. Carnot efficiency

D. Reversible work

Answer: C

208. The following factors are necessary to define a

thermodynamic cycle except

A. The working substance

B. High and low temperature reservoirs

C. The time it takes to complete the cycle

D. The means of doing work on the system

Answer: C

209. All of the following terms included in the second law for

open system except

A. Shaft work

B. Flow work

C. Internal work

D. Average work

Answer: D

210. The following terms are included in the first law of

thermodynamics for open systems except

A. Heat transferred in and out of the system

B. Work done by or in the system

C. Magnetic system

D. Internal system

Answer: C

211. The following terms are included in the first law of

thermodynamics for closed systems except

A. Heat transferred in and out of the system

B. Work done by or on the system

C. Internal energy

D. Kinetic energy

Answer: D

212. Which of the following statements about a path function is

not true?

A. On a p-v diagram, it can represent work done

B. On a t-s diagram, it can represent heat transferred

C. It is dependent on the between states of thermodynamic

equilibrium

D. It represents values of p, v, t, and s between states

that are path functions

Answer: D

213. A constant pressure thermodynamic process obeys:

A. Boyle’s law

B. Charles law

C. Amagat’s law

D. Delton’s law

Answer: B

214. The first and second laws of thermodynamics are:

A. Continuity equations

B. Momentum equations

C. Energy equations

D. Equations of state

Answer: C

215. Represents the temperature an ideal gas will attain when it

is brought to rest adiabatically.

A. Absolute zero temperature

B. Stagnation temperature

C. Boiling temperature

D. Critical temperature

Answer: B

216. Gauge pressure and absolute pressure differ from each other

by:

A. The system units

B. Atmospheric pressure

C. The size of the gauge

D. Nothing they mean the same thing

Answer: B

217. Each of the following are correct values of standard

atmospheric pressure except:

A. 1, 000 atm

B. 14.962 psia

C. 760 torr

D. 1013 mm Hg

Answer: D

218. All of the following are properties of an ideal gas except:

A. Density

B. Pressure

C. Viscosity

D. Temperature

Answer: C

219. Which of the following is not the universal gas constant?

A. 1545 ft-lb/lbmol-°R

B. 8.314 J/mol.K

C. 8314 kJ/mol.K

D. 8.314 kJ/kmol.K

Answer: C

220. The following are all commonly quoted values of standard

temperatures and pressure except:

A. 32°F and 14.696 psia

B. 273.15 K and 101.325 kPa

C. 0°C and 760 mm Hg

D. 0°C and 29.92 in Hg

Answer: D
221. The variation of pressure in an isobaric process is:

A. Linear with temperatures

B. Described by the perfect gas law

C. Inversely proportional to temperature

D. Zero

Answer: D

222. For fluid flow, the enthalpy is the sum of internal energy

and .

A. Entropy

B. Work flow

C. Pressure

D. Temperature

Answer: B

223. A thermodynamic process whose deviation from equilibrium is

infinitesimal at all times is .

A. Reversible

B. Isentropic

C. In quasi-equilibrium

D. Isentropic

Answer: C

224. Which thermodynamic property best describes the molecular

activity of a substance?

A. Enthalpy

B. Entropy

C. Internal energy

D. External energy

Answer: C

225. Stagnation enthalpy represents the enthalpy of a fluid when

it is brought to rest .

A. Isometrically

B. Adiabatically

C. Isothermally

D. Disobarically

Answer: B

226. During stagnation process, the kinetic energy of a fluid is

converted to enthalpy which results in an:

A. Increase in the fluid specific volume

B. Increase in the fluid pressure

C. Increase in the fluid temperature and pressure

D. Increase in the fluid temperature

Answer: C

227. The properties of fluid at the stagnation in state are

called .

A. Stagnation property

B. Stagnation phase

C. Stagnation state

D. Stagnation vapor

Answer: C

228. All of the following are thermodynamic properties except

A. Temperature

B. Pressure

C. Density

D. Modulus of elasticity

Answer: D

229. A liquid boils when its vapor pressure equals

A. The gage pressure

B. The critical pressure

C. The ambient pressure

D. One standard atmosphere

Answer: C

230. A system composed of ice and water at 0°C is said to be:

A. A multiphase material

B. In thermodynamic equilibrium

C. In thermal equilibrium

D. All of the above

Answer: D

231. The heat of fusion of a pure substance is:

A. The change in phase from solid to gas

B. The change in phase form liquid to gas

C. The energy released in a chemical reaction

D. The energy required to melt the substance

Answer: D

232. The heat of vaporization involves the change in enthalpy

due to:

A. The change in phase from solid to gas

B. The change in phase form liquid to gas

C. The energy released in a chemical reaction

D. The change in phase from solid to liquid

Answer: B

233. The heat of sublimation involves the change in enthalpy due

to:

A. The change in phase from solid to gas

B. The change in phase form liquid to gas

C. The energy released in a chemical reaction

D. The change in phase from solid to liquid

Answer: A

234. A specific property

A. Defines a specific variable (e.g., temperature)

B. Is independent of mass

C. Is an extensive property multiplied by mass

D. Is dependent of the phase of the substance

Answer: A

235. A material’s specific heat can be defined as:

A. The ratio of heat required to change the temperature

of mass by a change in temperature

B. Being different for constant pressure and constant

temperature processes

C. A function of temperature

D. All of the above

Answer: D

236. If a substance temperature is less than its saturation

temperature, the substance is:

A. Subcooled liquid

B. Wet vapor

C. Saturated vapor

D. Superheated vapor

Answer: A

237. If a substance temperature is equal to its saturation

temperature, the substance is a .

A. Subcooled liquid

B. Wet vapor
C. Saturated liquid and vapor

D. Superheated vapor

Answer: C

238. If a substance’s temperature is greater than its saturation

temperature, the substance is a .

A. Subcooled liquid

B. Wet vapor

C. Saturated vapor

D. Superheated vapor

Answer: D

239. Critical properties refer to

A. Extremely important properties, such as temperature

and pressure

B. Heat required for phase change and important for

energy production

C. Property values where liquid and gas phase are

indistinguishable

D. Properties having to do with equilibrium conditions,

such as the Gibbs and Helmholtz functions.

Answer: C

240. For a saturated vapor, the relationship between

temperature and pressure is given by:

A. The perfect gas law

B. Van der Waal’s equation

C. The steam table

D. A Viral equation of state

Answer: C

241. Properties of a superheated vapor are given by

A. The perfect gas law

B. A superheated table

C. A one to one relationship. Such as the properties

of saturated steam

D. A Viral equation of state

Answer: B

242. Properties of non-reacting gas mixtures are given by:

A. Geometric weighting

B. Volumetric weighting

C. Volumetric weighting for molecular weight and

density, and geometric weighting for all other

properties except entropy

D. Arithmetic average

Answer: C

243. The relationship between the total volume of a

mixture of non-reacting gases and their partial volume

given by:

A. Gravimetric fractions

B. Amagat’s law

C. Dalton’s law

D. Mole fractions

Answer: B

244. The relationship between the total pressure of a

mixture of non-reacting gases and the partial pressures of

constituents is given by:

A. Gravimetric fractions

B. Volumetric fractions

C. Dalton’s law
D. Mole fractions

Answer: C

245. Which of the following is the best definition of

enthalpy?

A. The ratio of heat added to the temperature

increases in a system

B. The amount of useful energy in a system

C. The amount of energy no longer available to the

system

D. The heat required to cause a complete conversion

between two phases at a constant temperature

Answer: B

246. Which of the following statements is not true for real

gases?

A. Molecules occupy a volume not negligible in

comparison to the total volume of gas

B. Real gases are subjected to attractive forces

between molecules (e.g., Van der Waal’s forces)

C. The law of corresponding states may be used for

real gases

D. Real gases are found only rarely in nature

Answer: D

247. The stagnation state is called the isentropic

stagnation state when the stagnation process is:

A. Reversible as well dynamic

B. Isotropic

C. Adiabatic

D. Reversible as well as adiabatic

Answer: D

248. The entropy of a fluid remains constant during what

process?

A. Polytropic stagnation process

B. Unsteady stagnation process

C. Combustion process

D. Isentropic stagnation process

Answer: D

249. All of the following processes are irreversible except

A. Stirring of a viscous liquid

B. An isentropic deceleration of a moving perfect

fluid

C. An unrestrained expansion of a gas

D. Phase changes

Answer: B

250. All of the following processes are irreversible except

A. Chemical reactions

B. Diffusion

C. Current flow through an electrical resistance

D. An isentropic compression of a perfect gas

Answer: D

251. All of the following processes are irreversible except

A. Magnetization with hysteresis

B. Elastic tension and release of a steel bar

C. Inelastic deformation

D. Heat conduction

Answer: B

252. Which of the following state(s) is/are necessary for a

system to be in thermodynamic equilibrium?

A. Chemical equilibrium

B. Thermal equilibrium

C. Mechanical equilibrium

D. Chemical, mechanical, and thermal equilibrium

Answer: D

253. Adiabatic heat transfer within a vapor cycle refers

to:

A. Heat transfer that is atmospheric but not

reversible

B. The transfer of energy from one stream to another

in a heat exchanger so that the energy of the

input streams equals the energy of the output

streams

C. Heat transfer that is reversible but not

isentropic

D. There is no such thing as adiabatic heat transfer

Answer: B

254. Which of the following gives polytropic under n?

A.

log𝑃2

𝑃1

log𝑉

𝑉2

B.

log𝑃1

𝑃2
log𝑉1

𝑉2

C.

log𝑉1

𝑉2

log𝑃

𝑃1

D.

log𝑉1

𝑉2

log𝑃

𝑃2

Answer: A

255. The work done in an adiabatic process in a system:

A. Is equal to the change in total energy in a

closed system

B. Is equal to the total net heat transfer plus the

entropy change

C. Is equal to the change in total energy of a

closed system plus the entropy change

D. Is equal to the change in total energy of a

closed system plus net heat transfer

Answer: D

256. Based on the first law of thermodynamics, which of the

following is wrong?

A. The heat transfer equals the work plus energy

change
B. The heat transfer cannot exceed the work done

C. The net transfer equal the net work of the cycle

D. The net heat transfer equals the energy change if

no work is done

Answer: B

257. Assuming the real processes, the net entropy change in

the universe:

A. Must be calculated

B. Equals zero

C. Is negative

D. Is positive

Answer: D

258. Which of the following types of flowmeters is most

accurate?

A. Venturi tube

B. Pitot tube

C. Flow nozzle

D. Foam type

Answer: B

259. What is referred by control volume?

A. An isolated system

B. Closed system

C. Fixed region in space

D. Reversible process only

Answer: C

260. What is the most efficient thermodynamic cycle?

A. Carnot

B. Diesel
C. Rankine

D. Brayton

Answer: A

261. How do you treat a statement that is considered a

scientific law?

A. We postulate to be true

B. Accept as a summary of experimental observation

C. We generally observed to be true

D. Believe to be derived from mathematical theorem

Answer: B

262. An instrument commonly used in most research and

engineering laboratories because it is small and fast among

the other thermometers.

A. Mercury thermometer

B. Liquid-in-glass thermometer

C. Gas thermometer

D. Thermocouple

Answer: D

263. In an actual gases, the molecular collisions are

A. Plastic

B. Elastic

C. Inelastic

D. Inplastic

Answer: C

264. Which of the following is used n thermal power plant?

A. Brayton

B. Reversed carnot

C. Rankine
D. Otto

Answer: C

265. The elongation and compression of a helical spring is

an example of

A. Irreversible process

B. Reversible process

C. Isothermal process

D. Adiabatic process

Answer: B

266. Otto cycle consists of

A. Two isentropic and two constant volume processes

B. Two isentropic and two constant pressure

processes

C. Two adiabatic and two isothermal processes

D. Two isothermal and two constant volume processes

Answer: A

267. Brayton cycle has

A. Two isentropic and two constant volume processes

B. Two isentropic and two constant pressure

processes

C. One constant pressure, one constant volume, and

two adiabatic processes

D. Two isothermal, one constant volume and constant

pressure processes

Answer: B

268. A Bell-Coleman cycle is a reversed

A. Stirling cycle

B. Joule cycle
C. Carnot cycle

D. Otto cycle

Answer: B

269. A steam nozzle changes

A. Kinetic energy into heat energy

B. Heat energy into potential energy

C. Heat energy into kinetic energy

D. Potential energy into heat energy

Answer: C

270. The pitot tube is a device used for measurement of

A. Pressure

B. Flow

C. Velocity

D. Discharge

Answer: C

271. The continuity equation is applicable to

A. Viscous, unviscous fluids

B. Compressibility of fluids

C. Conservation of mass

D. Steady, unsteady flow

Answer: C

272. The work done by a force of R Newtons moving in a

distance of L meters is converted entirely into kinetic

energy and expressed by the equation:

A. 𝑅𝐿 =

2𝑀𝑉 2

B. 𝑅𝐿 = 2𝑀𝑉

⬚
C. 𝑅𝐿

= 1

𝑀𝑉

D. 𝑅𝐿

= 1

𝑀𝑉

Answer: C

273. Gas being heated at constant volume is undergoing the

process of:

A. Isentropic

B. Adiabatic

C. Isometric

D. Isobaric

Answer: C

274. Dew point is defined as

A. The temperature to which the air must be cooled

at constant pressure to produce saturation

B. The point where the pressure and temperature

lines meet

C. The temperature which dew is formed in the air

D. The pressure which dew is formed in the air

Answer: A

275. What do you call the changing of an atom of element

into an atom of a different element with a different atomic

mass?

A. Atomization

B. Atomic transmutation

C. Atomic pile

D. Atomic energy

Answer: B

276. What do you call the weight of the column of air above

the earth’s surface?

A. Air pressure

B. Aerostatic pressure

C. Wind pressure

D. Atmospheric pressure

Answer: D

277. What keeps the moisture from passing through the

system?

A. Dehydrator

B. Aerator

C. Trap

D. Humidifier

Answer: A

278. What condition exists in an adiabatic throttling

process?

A. Enthalpy is variable

B. Enthalpy is constant

C. Entropy is constant

D. Specific volume is constant

Answer: B

279. The specific gravity of a substance is the ratio of

its density to the density of:

A. Mercury

B. Gas

C. Air

D. Water

Answer: D

280. A compound pressure gauge is used to measure:

A. Complex pressures

B. Variable pressures

C. Compound pressures

D. Positive and negative pressures

Answer: D

281. Isentropic flow is

A. Perfect gas flow

B. Ideal fluid flow

C. Frictionless reversible flow

D. Reversible adiabatic flow

Answer: D

282. Under ideal conditions, isothermal, isobaric,

isochoric and adiabatic processes are:

A. Dynamic processes

B. Stable processes

C. Quasi-static processes

D. Static processes

Answer: C

283. One Watt is:

A. 1

𝑁.𝑚
𝑠

B. 1

𝑁.𝑚

𝑚𝑖𝑛

C. 1

𝑁.

ℎ𝑟

D. 1

𝑘𝑁.𝑚

Answer: A

284. A temperature above which a given gas cannot be

liquefied:

A. Cryogenic temperature

B. Vaporization temperature

C. Absolute temperature

D. Critical temperature

Answer: D

285. The effectiveness of a body as a thermal radiator at a

given temperature.

A. Absorptivity

B. Emissivity

C. Conductivity

D. Reflectivity

Answer: B

286. Which of the following occurs in a reversible

polytropic process?

A. Enthalpy remains constant

B. Internal energy does not change

C. Some heat transfer occurs

D. Entropy remains constant

Answer: C

287. The instrument used to measure atmospheric pressure

is:

A. Rotameter

B. Manometer

C. Venturi

D. Barometer

Answer: D

288. A pneumatic tool is generally powered by

A. Water

B. Electricity

C. Steam

D. Air

Answer: D

289. Which of the following gases can be used to measure

the lowest temperature?

A. Nitrogen

B. Helium

C. Oxygen

D. Hydrogen

Answer: B

290. The triple point of a substance is the temperature and

pressure at which :

A. The solid and liquid phases are in equilibrium

B. The solid and gaseous phases are in equilibrium

C. The solid, liquid and gaseous phases are in

equilibrium

D. The solid does not melt, the liquid does not boil

and the gas does not condense

Answer: D

291. Which of the following is not applicable in a free

expansion process?

A. Heat rejected is zero

B. Work done is zero

C. Change in temperature is zero

D. Heat supplied is zero

Answer: C

292. Ericson cycle has

A. Two isothermal and two constant pressure

processes

B. Two isothermal and two constant volume processes

C. Two isothermal and two constant entropy processes

D. Two adiabatic, one constant volume and constant

pressure processes

Answer: A

293. Stirling cycle has

A. Two adiabatic and two constant volume processes

B. Two adiabatic and two constant pressure processes

C. Two isothermal and two constant pressure

processes

D. Two isothermal and two constant volume processes

Answer: D

294. The temperature of the fluid flowing under pressure

through a pipe is usually measured by:

A. A glass thermometer

B. An electric resistance thermometer

C. A thermocouple

D. All of the above

Answer: D

295. Specific heat capacity is an SI derived unit described

as:

A.

𝑘𝑔

B.

𝑚𝐾

C.

𝑘𝐽

𝑘𝑔𝐾

D.

Answer: C

296. Which of the following is mathematically a

thermodynamic property?

A. A point function

B. Discontinuous

C. A path function

D. Exact differential

Answer: A
297. When the expansion or compression of gas takes place

“without transfer of heat” to or from the gas, the process

is called:

A. Reversible

B. Adiabatic

C. Polytropic

D. Isothermal

Answer: B

298. Another name for the liquid valve is:

A. Freon valve

B. Shut-off valve

C. King valve

D. Master valve

Answer: C

299. A liquid whose temperature is lower than the

saturation temperature corresponding to the existing

pressure:

A. Subcooled liquid

B. Saturated liquid

C. Pure liquid

D. Compressed liquid

300. The law that states “Entropy of all perfect crystalline

solids is zero at absolute zero temperature”.

A. Zeroth Law of Thermodynamics

B. First Law of Thermodynamics

C. Second Law of Thermodynamics

D. Third Law of Thermodynamics

Answer: Third Law of Thermodynamics

301. What should be the temperature of both water and steam

whenever they are present together?

A. Saturation temperature for the existing pressure

B. Boiling point of water at 101.325 kPa

C. Superheated temperature

D. One hundred degrees centigrade

Answer: A. Saturation temperature for the existing pressure

302. A manometer is an instrument that is used to measure:

A. air pressure

B. heat radiation

C. condensate water level

D. air volume

Answer: A. air pressure

303. What is the area under the curve of a temperature entropy

diagram?

A. Volume

B. Heat

C. Work

D. Entropy

Answer: B. Heat

304. What do bodies at a temperature above absolute zero emit?

A. Energy

B. Heat of convection

C. Thermal radiation

D. Heat of compression

Answer: C. Thermal radiation

305. 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. Carnot cycle

B. Otto cycle

C. Diesel Cycle

D. Rankine Cycle

Answer: A. Carnot cycle

306. Both Stirling and Ericson engines are

A. internal combustion engines

B. external combustion engines

C. Carnot engines

D. Brayton engines

Answer: B. external combustion engines

307. Nozzles does not involve any work interaction. The fluid

through this device experiences

A. no change in potential energy

B. no change in kinetic energy

C. no change in enthalpy

D. vacuum

Answer: A. no change in potential energy

308. If the actual kinetic energy of a nozzle is Ka and Ki is

the maximum value that can be attained by an isentropic

expansion from an initial to final state, then the efficiency of

the nozzle is:

A.

𝐾𝑖

𝐾𝑎

B.

𝐾𝑎−𝐾𝑖
𝐾𝑎

C.

𝐾𝑎−𝐾𝑖

𝐾𝑖

D.

𝐾𝑎

𝐾𝑖

Answer: D.

𝐾𝑎

𝐾𝑖

309. The convergent section of a nozzle increases the velocity

of the flow of the gas. What does it do on its pressure?

A. Pressure becomes constant

B. Pressure equals the velocity

C. It increases the pressure

D. It decreases the pressure

Answer: D. It decreases the pressure

310. In a closed vessel, when vapoization takes place, the

temperature rises. Due to the rising temperature, the pressure

increases until an equilibrium is established between the

temperature and pressure. The temperature of equilibrium is

called .

A. dew point

B. ice point

C. boiling point

D. superheated temperature

Answer: C. boiling point

311. At steam point, the temperatures of water and its vapor at

standard pressure are:

A. extremes or maximum

B. unity

C. in equilibrium

D. undefined

Answer: C. in equilibrium

312. When hot soup was served in a cup during dinner, an

engineer was so eager to drink it. Since it was hot, he added

cubes of ice to cool the soup and stirred it. He noticed that

dew starts to form on the outermost surface of the cup. He

wanted to check the temperature of the outermost surface of the

cup. What is this temperature equal to?

A. Superheated temperature

B. Equal to zero

C. Standard temperature

D. Equal to air’s dew point temperature

Answer: D. Equal to air’s dew point temperature

313. What do you call a conversion technology that yields

electricity straight from sunlight without the aid of a working

substance like gas or steam without the use of any mechanical

cycle?

A. Power conversion

B. Stirling cycle conversion

C. Solar thermal conversion

D. Photovoltaic-energy conversion

Answer: D. Photovoltaic-energy conversion

314. Which of the following property of liquid extend resistance

to angular or shear deformation:

A. Specific gravity

B. Specific weight

C. Viscosity

D. Density

Answer: C. Viscosity

315. What is the pressure at the exit of a draft tubein a

turbine?

A. Below atmospheric

B. Above atmospheric

C. Atmosphere

D. Vacuum

Answer: C. Atmosphere

316. When changes in kinetic energy of a compressed gas are

negligible or insignificant, the work input to an adiabatic

compressor is .

A. negligible

B. zero

C. infinity

D. equal to change in enthalpy

Answer: D. equal to change in enthalpy

317. What is the area under the curve of a pressure-volume

diagram?

A. Nonflow work

B. Steadyflow work

C. Heat

D. Power

Answer: A. Nonflow work

318. In Stirling and Ericson cycle, regeneration can

A. increase efficiency

B. decrease efficiency

C. control efficiency

D. limit efficiency

Answer: A. increase efficiency

319. The first law of thermodynamics is based on which of the

following principles?

A. Conservation of mass

B. Enthalpy-entropy relationship

C. Entropy-temperature relationship

D. Conservation of energy

Answer: D. Conservation of energy

320. In a two-phase system, 30% moisture means

A. 70% liquid and 30% vapor

B. 70% vapor and 30% liquid

C. 30% liquid and 100%vapor

D. 30% vapor and 100% liquid

Answer: B. 70% vapor and 30% liquid

321. At 101.325 kPa, the boiling point of water is 100◦C. If the

pressure is decreased the boiling temperature will:

A. increase

B. decrease

C. remain the same

D. drop to zero

Answer: B. decrease

322. Which of the following is equivalent to 1 hp in Btu/hr?

A. 778

B. 2545
C. 746

D. 3.41

Answer: B. 2545

323. What is the pressure above zero?

A. Gage pressure

B. Absolute pressure

C. Vacuum pressure

D. Atmospheric pressure

Answer: A. Gage pressure

324. One Newton – meter is equal to:

A. 1 Joule

B. 1 Btu

C. 1 Calorie

D. 1 Ergs

Answer: A. 1 Joule

325. Which of the following is the instrument used to measure

fluid velocity?

A. Pitot tube

B. Orsat apparatus

C. Anemometer

D. Viscosimeter

Answer: A. Pitot tube

326. Cryogenic temperature ranges from:

A. -150◦F to -359◦F

B. -250◦F to -459◦F

C. -100◦F tp -300◦F

D. -200◦F to -400◦F
Answer: B. -250◦F to -459◦F

327. Steam at 2 kPa is saturated at 17.5◦C. In what state will

the state be at 40◦C if the pressure is 2.0 kPa?

A. Superheated

B. Saturated

C. Subcooled

D. Supersaturated

Answer: A. Superheated

328. Acceleration is proportional to force

A. Newtons law

B. Archimedes principle

C. Law of gravitation

D. Theory of relativity

Answer: A. Newtons law

329. Which of the following could be defined as simple push and

pull?

A. Power

B. Inertia

C. Work

D. Force

Answer: D. Force

330. The true pressure measured above a perfect vacuum is:

A. absolute pressure

B. atmospheric pressure

C. gauge pressure

D. vacuum pressure

Answer: A. absolute pressure

331. If an initial volume of an ideal gas is compressed to onehalf its

original volume and to twice its original temperature,

the pressure :

A. doubles

B. halves

c. Quadruples

D. Triples

Answer: C. Quadruples

332. When the expansion or compression of gas takes place

without transfer of heat to or from the gas, the process is

called

A. Isometric process

B. Isothermal process

C. Isobaric process

D. Adiabatic process

333. A body radiates heat proportional to the fourth power of

its absolute temperature

A. Stefan-Boltzmann Law

B. Planck's Law

C. Kirchhoff's Law

D. Maxwell's Law

Answer: A. Stefan-Boltzmann Law

334. All substances emit radiation, the quantity and quality of

which depends upon the absolute temperature and the properties

of the material, composing the radiating body.

A. Stefan-Boltzmann Law

B. Planck's Law

C. Kirchhoff's Law

D. Maxwell's Law
Answer: B. Planck's Law

335. For bodies in thermal equilibrium with the environment, the

ratio of total emissive power to the absorptivity is constant at

any temperature.

A. Stefan-Boltzmann Law

B. Planck's Law

C. Kirchhoff's Law

D. Maxwell's Law

Answer: C. Kirchhoff's Law