CHAPTER 1 - THERMODYNAMICS

1. PAST BOARD QUESTION

Enthalpy of an ideal gas is a function only of ______.
A. entropy
B. internal energy
C. temperature
D. pressure

Answer: C

2. PAST BOARD QUESTION

Which of the following is the most efficient thermodynamic cycle?
A. Brayton
B. Otto
C. Carnot
D. Diesel

Answer: C

3. PAST BOARD QUESTION

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

4. PAST BOARD QUESTION

An ideal gas is compressed isothermally. What is the enthalpy change?
A. always negative
B. always positive
C. zero
D. undefined

Answer: C

5. PAST BOARD QUESTION

What is the name of the process that has no heat transfer?
A. Isothermal
B. Isobaric
C. Polytropic
D. Adiabatic

Answer: D

6. PAST BOARD QUESTION

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. remain constant
D. is zero

Answer: B

7. PAST BOARD QUESTION

What is the SI unit of pressure?
A. kg/sq cm
B. dynes/sq cm
C. Pascal
D. Psi

Answer: C

8. PAST BOARD QUESTION

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

9. PAST BOARD QUESTION

In the flow process, 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

10. PAST BOARD QUESTION

It is the mechanical energy of pressure that is transformed into energy of heat.
A. Kinetic energy
B. Enthalpy
C. Heat exchanger
D. Heat of compression

Answer: B

11. PAST BOARD QUESTION

If Joule Thompson coefficient is equal to zero, then the process will become
A. isentropic
B. isobaric
C. isenthalpic
D. Isothermal

Answer: D

12. PAST BOARD QUESTION

If the fluid will pass through a nozzle, then its entropy will
A. increase
B. remain the same
C. decrease
D. become infinite

Answer: B

13. PAST BOARD QUESTION

Which of the following converts fossil fuels into shaft work?
A. Nuclear power plant
B. Gas turbine power plant
C. Dendrothermal power plant
D. Thermal power plant

Answer: D

14. PAST BOARD QUESTION

Dissolve gases like _____ will make water corrosive and react with metal to form iron oxide.
A. O2 and N2
B. O2 and CO
C. O2 and CO2
D. N2 and SO2

Answer: C

15. PAST BOARD QUESTION

What is the critical temperature of mercury?
A. 1160 °C
B. 1260 °C
C. 1360 °C
D. 1460 °C

Answer: D

16. PAST BOARD QUESTION

What is the critical pressure of mercury?
A. 100 MPa
B. 108 MPa
C. 128 MPa
D. 158 MPa

Answer: B

17. PAST BOARD QUESTION

What is the method used in converting heat directly to electricity by magnetism?
A. Electromagnetic induction
B. Magnetodynamic
C. Magnetohydrodynamic
D. Thermoelectric

Answer: C

18. PAST BOARD QUESTION

Which of the following is NOT a material used for thermoelectric elements?
A. Bismuth telluride
B. Lead telluride
C. Zinc telluride
D. Germanium

Answer: C

19. PAST BOARD QUESTION

The law which states that "when conductor and a magnetic field move relatively to each other, an
electric voltage is induced in the conductor".
A. Maxwell's law
B. Kirchoff's law
C. Faraday's law
D. Voltage's law

Answer: C

20. PAST BOARD QUESTION

It is a device that transfers heat directly to electrical energy by utilizing thermionic emissions.
A. Thermionic cell
B. Thermionic generator
C. Thermionic converter
D. Thermionic motor

Answer: B

21. PAST BOARD QUESTION

The theory of changing heat into mechanical work.
A. Thermodynamics
B. Kinematics
C. Inertia
D. Kinetics

Answer: A

22. PAST BOARD QUESTION

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

23. PAST ME BOARD QUESTION

Which of the following cycles consists two isothermal and two constant volume processes?
A. Diesel cycle
B. Ericsson cycle
C. Stirling cycle
D. Otto cycle

Answer: C

24. PAST BOARD QUESTION

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

25. PAST BOARD QUESTION

In the polytropic process, PVn = Constant, which of the following is the process if the value of n
is infinitely large?
A. isobaric
B. isometric
C. isothermal
D. polytropic
Answer: B

26. PAST BOARD QUESTION

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

27. PAST BOARD QUESTION

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

28. PAST BOARD QUESTION

Number of molecules in a mole of any substance is a constant called _______.
A. Rankine constant
B. Avogadro's number
C. Otto constant
D. Thompson constant

Answer: B

29. PAST BOARD QUESTION

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

30. PAST BOARD QUESTION

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

31. PAST BOARD QUESTION

Heat exchangers typically involve _______.
A. no work interactions
B. no heat interactions
C. no energy interactions
D. none of these

Answer: A

32. PAST BOARD QUESTION

What device is used to convert the heat to work?
A. adiabatier
B. regenerator
C. heat engines
D. generator

Answer: C

33. PAST BOARD QUESTION

The objective of a heat pump is to maintain a heated space at ________.
A. low temperature
B. high temperature
C. medium temperature
D. none of these
Answer: B

34. PAST BOARD QUESTION

What device that violates the second law of thermodynamics?
A. perpetual motion machine of second kind
B. perpetual motion machine of third kind
C. perpetual-motion machine of the first kind
D. none of these

Answer: A

35. PAST BOARD QUESTION

How do you call the process if no irreversibilities that occur outside the system boundaries?
A. externally reversible
B. internally reversible
C. reversible
D. none of these

Answer: A

36. PAST BOARD QUESTION

It is an energy interaction that is not accompanied by entropy transfer.
A. energy interchange
B. heat
C. work
D. none of these

Answer: C

37. PAST BOARD QUESTION

A ________ is used in aircraft engines and some automotive engine. In this method, a turbine
driven by the exhaust gases is used to provide power to compressor or blower at the inlet.
A. discharging
B. turbocharging
C. supercharging
D. scavenging

Answer: B
38. PAST BOARD QUESTION
The only devices where the changes in kinetic energy are significant.
A. compressor C. pumps
B. nozzles and diffusers D. none of these

Answer: B

39. PAST BOARD QUESTION

This is the device used to transfer heat from low temperature medium to a high temperature
A. adiabatic
B. refrigerator
C. heat exchanger
D. heat pump

Answer: D

40. PAST BOARD QUESTION

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

41. PAST BOARD QUESTION

The latent heat of vaporization for water in Joules per kg is equal to
A. 5.4 × 102
B. 4.13 × 103
C. 22.6 × 105
D. 3.35 × 105

Answer: C

42. PAST ME BOARD QUESTION

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

43. PAST BOARD QUESTION

If the temperature is held constant and the pressure is increased beyond the saturation pressure,
then, the working medium must be _________.
A. saturated vapor
B. compressed liquid
C. saturated liquid
D. subcooled liquid

Answer: B

44. PAST BOARD QUESTION

Is the condition of pressure and temperature at which a liquid and its vapor are indistinguishable.
A. Critical point
B. Dew point
C. Absolute humidity
D. Relative humidity

Answer: A

45. PAST BOARD QUESTION

When a substance in gaseous state is below the critical temperature, it is called
A. vapor C. cloud
B. moisture D. steam

Answer: A

46. PAST BOARD QUESTION

Superheated vapor behaves
A. just as gas
B. just as steam
C. just as ordinary vapor
D. approximately as a gas

Answer: D

47. PAST BOARD QUESTION

Which 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

48. PAST BOARD QUESTION

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

49. PAST BOARD QUESTION

Heat normally flowing from a high temperature body to a low temperature body wherein it is
impossible to 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

50. PAST BOARD QUESTION

Work is ________ between the system and the surroundings.
A. work interaction
B. energy interaction
C. heat interaction
D. none of these

Answer: B

51. PAST BOARD QUESTION

It is the process by which the system remains in equilibrium at all times.
A. quasi-equilibrium
B. static equilibrium
C. dynamic equilibrium
D. all of these

Answer: A

52. PAST BOARD QUESTION

In the absence of any work interactions between a system and its surroundings, the amount of net
heat transfer is equal _______.
A. to the change in the total energy of a closed system
B. to heat and to work
C. energy interactions
D. entropy change

Answer: A

53. PAST BOARD QUESTION

The constant volume and constant pressure specific heats are identical for _________.
A. compressible substance
B. incompressible substance
C. compressible gas
D. slightly compressible gas

Answer: B

54. PAST BOARD QUESTION

For steady flow devices, what happens to the volume of the control volume?
A. increase
B. decrease
C. constant
D. exponential in its increase

Answer: C

55. PAST BOARD QUESTION

A vapor having a temperature higher than the saturation temperature corresponding to the
existing pressure is called _________.
A. Superheated Vapor
B. Saturated Vapor
C. Wet vapor
D. Sub-cooled Vapor

Answer: A

56. PAST BOARD QUESTION

How do you call the work done in pushing a fluid across a boundary, usually into or out of a
system?
A. Mechanical work
B. Nonflow work
C. Flow work
D. Electrical work

Answer: C

57. PAST BOARD QUESTION

A liquid that has a temperature lower than the saturation temperature corresponding to the
existing pressure a called ________.
A. Subcooled liquid
B. Saturated liquid
C. superheated liquid
D. Water

Answer: A

58. PAST BOARD QUESTION

Since it is done by the fluid, the work done in a turbine is ________.
A. positive
B. negative
C. zero
D. infinite

Answer: A

59. PAST BOARD QUESTION

This law states that "all energy received as heat by a heat-engine cannot be converted into
mechanical work
A. 1st Law of Thermodynamics
B. 2nd Law of Thermodynamics
C. 3rd Law of Thermodynamics
D. All of the above

Answer: B

60. PAST BOARD QUESTION

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

61. PAST BOARD QUESTION

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

62. PAST BOARD QUESTION

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

63. PAST BOARD QUESTION

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

64. PAST BOARD QUESTION

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

65. PAST BOARD QUESTION

Is one whose pressure is higher than the saturation pressure corresponding to its temperature.
A. Compressed liquid
B. Saturated liquid
C. Saturated vapor
D. Superheated vapor

Answer: A

66. PAST BOARD QUESTION

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

67. PAST BOARD QUESTION

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

68. PAST BOARD QUESTION

The intensity of pressure that is measured above zero is called
A. Gage pressure
B. Absolute pressure
C. Vacuum pressure
D. Saturation pressure

Answer: B

69. PAST BOARD QUESTION

This is the ratio of the heat equivalent of the brake or useful horsepower developed by an engine
and available on its crankshaft, to the heat during at the same time.
A. Brake engine efficiency
B. Combined thermal efficiency
C. Indicated thermal efficiency
D. Brake thermal efficiency

Answer: D

70. PAST BOARD QUESTION

Flow work is equal to pressure times __________.
A. temperature
B. entropy
C. internal energy
D. specific volume

Answer: D

71. PAST BOARD QUESTION

Another term for constant volume process.
A. isometric
B. isochoric
C. isovolumic
D. all of these

Answer: D

72. PAST BOARD QUESTION

How do you call the passing from the solid phase directly into vapor phase?
A. condensation
B. fusion
C. sublimation
D. aeration

Answer: C

73. PAST BOARD QUESTION

In his experiment, Robert Boyle observed that in a vacuum chamber, the pressure of gasses is
inversely proportional to their ________.
A. temperature
B. pressure
C. volume
D. density

Answer: C

74. PAST BOARD QUESTION

It is an energy in transition.
A. Heat
B. Work
C. Power
D. None of these

Answer: A

75. PAST BOARD QUESTION

How do you call a system that is completely impervious to its surrounding? It is where neither
mass nor energy cross its boundaries.
A. Open system
B. Closed system
C. Adiabatic system
D. Isolated system

Answer: D

76. PAST BOARD QUESTION

It is the device used to measure small and moderate pressure difference.
A. Manometer
B. Bourdon gauge
C. Barometer
D. Piezometer

Answer: A

77. PAST BOARD QUESTION

A pressure of 1 millibar is equivalent to __________.
A. 1000 dynes/sq. cm
B. 1000 cm of Hg
C. 1000 psi
D. 1000 kg/sq. cm

Answer: A

78. PAST BOARD QUESTION

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

79. PAST BOARD QUESTION

Which of the engine is used for fighter bombers?
A. Turbojet
B. Pulsejet
C. Rockets
D. Ramjet

Answer: A

80. PAST BOARD QUESTION

Exhaust gases from an engine posses __________.
A. solar energy
B. kinetic energy
C. chemical energy
D. stored energy

Answer: B

81. PAST BOARD QUESTION

At critical point the latent enthalpy of vaporization is ________.
A. temperature dependent
B. zero
C. minimum
D. maximum

Answer: B

82. PAST BOARD QUESTION

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

83. PAST BOARD QUESTION

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

84. 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

85. 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

86. 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

87. PAST BOARD QUESTION

As the air passes through a nozzle, which of the following will decrease?
A. density
B. entropy
C. internal energy
D. Mach number

Answer: C

88. PAST BOARD QUESTIONS

The thermodynamic process wherein temperature is constant and the change in internal energy is
zero.
A. Isobaric process
B. Isometric process
C. Isothermal process
D. Polytropic process

Answer: C

89. PAST BOARD QUESTIONS

As the air passes through a diffuser, which of the following will decrease?
A. temperature
B. enthalpy
C. internal energy
D. Mach number

Answer: D

90. PAST BOARD QUESTION

It is the energy or storage capacity for performing work possessed by a moving body and by
virtue of its momentum.
A. Internal energy
B. Work
C. Gravitational potential energy
D. Kinetic energy

Answer: D

91. PAST BOARD QUESTION

After passing through a convergent-divergent nozzle, the temperature of air will _________.
A. increase
B. decrease
C. remains the same
D. slightly increase

Answer: B

92. PAST BOARD QUESTION

By increasing the temperature source of Carnot cycle, which of the following will not be
affected?
A. efficiency
B. work
C. heat added
D. heat rejected

Answer: D

93. PAST BOARD QUESTION

After passing through a convergent-divergent nozzle, the Mach number of air will _______.
A. increase
B. decrease
C. remains the same
D. become infinitely large

Answer: B

94. On what plane is the Mollier diagram plotted?

A. p-V
B. p-T
C. h-s
D. h-u

Answer: C

95. The compressibility factor z is used for predicting the behavior of non-ideal gases. How is
the 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

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

Answer: C

97. What is the expression for heat of vaporization?

A. hg
B. hf
C. hg - hf
D. hf - hg

Answer: C

98. What is the value of the work done for a closed, reversible, isometric system?
A. Zero
B. Positive
C. Negative
D. Indeterminate

Answer: A
99. What is the equation for the work done by a constant temperature system?
A. W = mRT In(V2-V1 )
B. W = mR (T1-T2) In(V2/V1)
C. W = MRT In(V2/V1)
D. W = RT In(V2/V1 )

Answer: C

100. What is true about the polytropic exponent n for a perfect gas undergoing an isobaric
process?
A. n > 0
B. n < 0
C. n = ∞
D. n = 0

Answer: D

101. PAST BOARD QUESTION

How does an adiabatic process compare to an isentropic process?
A. Adiabatic: Heat transfer = 0, Isentropic: Heat transfer = 0
B. Adiabatic: Heat transfer = 0, Isentropic: Heat transfer = 0
C. Adiabatic: Reversible, Isentropic: Not reversible
D. Both: Heat transfer = 0, Isentropic: Reversible

Answer: D

102. During an adiabatic, internally reversible process, what is true 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

103. For an irreversible process, what is true about the change in entropy of the system and
surroundings?
A. ds = dq/dt
B. ds = 0
C. ds > 0
D. ds < 0

Answer: C

104. PAST BOARD QUESTION

By decreasing the temperature sink of Carnot cycle, which of the following will not be affected?
A. efficiency
B. work
C. heat added
D. heat rejected

Answer: C

105. PAST BOARD QUESTION

The efficiency of Carnot cycle depends upon the _____________.
A. pressure
B. entropy
C. volume
D. temperature

Answer: D

106. PAST BOARD QUESTION

Is the heat required in constant-pressure process to completely vaporize a unit mass of liquid at a
given temperature.
A. Latent heat of vaporization
B. Enthalpy of transformation
C. Enthalpy of vaporization
D. All of the above

Answer: D

107. PAST BOARD QUESTION

Is a commonly used device for measuring temperature differences or high temperatures.
A. Thermistor
B. Thermocouple
C. Bimettalic strip
D. Mercury glass

Answer: B

108. PAST BOARD QUESTION

The science and technology concerned with precisely measuring energy and enthalpy.
A. Thermodynamics
B. Chemistry
C. Calorimetry
D. None of the above

Answer: C

109. PAST BOARD QUESTION

The efficiencies of all reversible heat engines operating between the same reservoirs
_____________.
A. Differ
B. Are the same
C. Are unequal
D. None of the above

Answer: B

110. PAST BOARD QUESTION

A process with no heat transfer is known as ___________.
A. Isobaric process
B. Adiabatic process
C. Isothermal process
D. Isometric process

Answer: B

111. PAST BOARD QUESTION

The relative density of a substance is the ratio of the density to the density of
A. Mercury
B. Oil
C. Gas
D. Water
Answer: D

112. PAST BOARD QUESTION

What is required to raise the temperature of 1 lb of water from 32° to 212 °F?
A. 144 Btu
B. 180 Btu
C. 970.3 Btu
D. Saturated heat

Answer: B

113. For which type of process does the equation dQ = Tds hold?
A. Irreversible
B. Reversible
C. Isobaric
D. Isothermal

Answer: B

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

A. ΔS (Surrounding) + ΔS (System) > 0
B. ΔS (Surrounding) + ΔS (System) < 0
C. ΔS (Surrounding) + ΔS (System) ≤ 0
D. ΔS (Surrounding) + ΔS (System) ≥ 0

Answer: D

115. The ideal reversible Carnot cycle involves four basic processes. What type of process are
they?
A. All isothermal
B. All adiabatic
C. All isentropic
D. Two isothermal and two isentropic

Answer: D
116. What is the temperature difference of the cycle if the entropy difference is ΔS, and the work
done is W?
A. W - ΔS
B. W / ΔS
C. ΔS / W
D. ΔS – W

Answer: B

117. 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

118. Which of the following statements regarding Rankine cycle is not true
A. Use of a condensable vapor in the cycle increase the efficiency of the cycle.
B. The temperatures 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

119. 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

120. 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

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

A. Pa
kg
B.
m−s
C. bars
kg f
D. 2
m

Answer: B

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

A. Newton meter
B. kg m/s2
C. unit of power
D. rate of change of energy

Answer: A

123. PAST BOARD QUESTIONS

Increasing the pressure has what effect of the boiling point of water?
A. No change
B. Temperature will be lowered
C. Temperature will be raised
D. Temperature will increase 2 °F for every psi

Answer: C

124. PAST BOARD QUESTIONS

Hydronic heat is _____________.
A. Steam heat
B. Hot water heat
C. Radiant heat
D. Heat of evaporation
Answer: B

125. PAST BOARD QUESTIONS

Which if the following most closely defines sensible heat?
A. An established relationship comparing any substance to the heat content of water
B. Heat quantity that can be felt or measured by a thermometer
C. Heat quantity above the point of saturation
D. Measure of heat intensity

Answer: B

126. PAST BOARD QUESTIONS

The term enthalpy ______________.
A. Is only used for the properties of refrigerant vapor
B. Is considered by Gibb’s Rule
C. Will measure, by its change, the quantity of heat added when refrigerant is vaporized at
constant
pressure
D. Defines the gas equation

Answer: C

127. PAST BOARD QUESTIONS

The quantity of heat required to change the state, as solid or liquid, of a body without rise of
temperature is called _____________.
A. Specific heat
B. Latent heat
C. Sensible heat
D. Required heat

Answer: B

128. PAST BOARD QUESTIONS

In the centigrade scale the coefficient of expansion of air per degree is ______.
A. 1/260
B. 1/304
C. 1/273
D. 1/360

Answer: C

129. PAST BOARD QUESTIONS

What are the two most common gases employed in Stirling and Ericsson cycles?
A. Air and helium
B. Hydrogen and helium
C. Oxygen and helium
D. Nitrogen and helium

Answer: B

130. PAST BOARD QUESTIONS

In Ericsson cycle, the regeneration process occurs during ___________ process.
A. Constant volume
B. Constant temperature
C. Constant pressure
D. None of these

Answer: C

131. PAST BOARD QUESTIONS

It used as working fluid in high-temperature applications of vapor cycles.
A. Helium
B. Deuterium
C. Mercury
D. Water

Answer: C

132. PAST BOARD QUESTIONS

Stirling cycle uses a ___________ as working fluids.
A. Incompressible gas
B. Incompressible fluids
C. Compressible refrigerant
D. Compressible fluids
Answer: D

133. 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

134. The state of a thermodynamic system is always defined by its _______.

A. absolute temperature
B. process
C. properties
D. temperature and pressure

Answer: C

135. 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

136. Entropy is the measure of

A. the internal energy of a gas
B. the heat capacity of a substance
C. randomness or disorder
D. the change of enthalpy of a system

Answer: C

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

A. Entropy of a mixture is greater than that of its 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

138. 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

139. Energy changes are represented by all except which one of the following
A mCpdt
B. -∫ VdP
C. Tds − PdV
dQ
D.
T

Answer: D

140. A rigid container is heated by the sun. There is no shaft work associated with the container.

From the First Law of thermodynamics, you determine the resulting work to be _________.
A. equal to the heat transfer
B. equal to the change in internal energy
C. equal to the volume times the change in pressure
D. equal to zero

Answer: D

141. In flow process, neglecting KE and PE changes. ∫ vdP represents which item below?
A. Heat transfer
B. Shaft work
C. Enthalpy change
D. Closed system work
Answer: B

142. Power may be expressed in units of

A. ft−b
B. kW−hr
C. Btu
D. Btu/hr

Answer: D

143. PAST BOARD QUESTION

In Stirling process the heat is added during __________.
A. isobaric process
B. isentropic process
C. isothermal process
D. heat process

Answer: C

144. PAST BOARD QUESTION

Increasing the pressure has what effect of the boiling point of water?
A. No change
B. Temperature will be lowered
C. Temperature will be raised
D. Temperature will increase 2 °F for every psi

Answer: C

145. PAST BOARD QUESTION

Heat absorbed by water when it changes from liquid to steam at the boiling point is called
_______.
A. sensible heat
B. latent heat
C. specific heat
D. superheat

Answer: B
146. PAST BOARD QUESTION
Steam at 100 psi and 400 °F is ________.
A. saturated
B. wet
C. superheated
D. none of the above

Answer: C

147. PAST BOARD QUESTION

The enthalpy of a substance at a specified state due to its chemical composition.
A. enthalpy of reaction
B. enthalpy of combustion
C. enthalpy of formation
D. enthalpy of vaporization

Answer: C

148. Equilibrium condition exist in all except which of the following?

A. In reversible processes
B. In processes where driving forces are infinitesimals
C. In a steady state flow process
D. Where nothing can occur without an effect on the system’s surrounding

Answer: C

149. In a closed system (with a moving boundary) which of the following represents work done
during an isothermal process?
A. W = 0
B. W = P(V2 - V1)
V2
C. W = P1V1 In
V1
P 2 V 2−P1 V 1
D. W =
1−n

Answer: C
150. A substance that is homogeneous in composition 45 45 and homogeneous and invariable in
chemical aggregation
A. Pure substance
B. Simple substance
C. Vapor
D. Water

Answer: A

151. A substance whose state is defined by variable Intensive thermodynamic properties.

A. Pure substance
B. Simple substance
C. Vapor
D. Water

Answer: B

152. 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

153. 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

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

A. Open system
B. Closed system.
C. Isolated system
D. Steady flow system

Answer: A

155. The properties that are dependent upon the mass of the system and are total values such as
total volume and total internal energy.
A. Intensive properties
B. Extensive properties
C. Specific properties
D. State properties

Answer: B

156. 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

157. 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. Thermodynamics Property

Answer: C

158. 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

159. Avogadro’s number, a fundamental constant of nature, is the number of molecules in a gram
mole. This constant is
A. 6.05222 × 1023
B. 6.02252 × 102
C. 6.20522 × 1021
D. 6.50222 × 1021

Answer: B

160. 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

161. The absolute zero on the Fahrenheit scale is at

A. –459.7 °F
B. 459.7 F
C. –273.15°C
D. 273.15 °C

Answer: A

162. Absolute temperatures on the Fahrenheit scale.

A. degrees Rankine
B. degrees Kelvin
C. absolute Fahrenheit
D. absolute Celsius

Answer: A

163. The absolute zero on the Celsius scale is at

A –459.7 °F
B. 459.7 deg °F
C. –273.15 deg °C
D. 273.15 deg °C

Answer: C

164. What is the absolute temperature in Celsius scale?

A. degrees Rankine
B. degrees Kelvin
C. absolute Fahrenheit
D. absolute Celsius

Answer: B

165. The Fahrenheit scale was introduced by Gabriel Fahrenheit of Amsterdam, Holland in what
year?
A. 1592
B. 1742
C. 1730
D. 1720

Answer: D

166. The Centigrade scale was introduced by Anders Celsius in what year?
A. 1542
B. 1740
C. 1730
D. 1720

Answer: B

167. The National Bureau of Standards uses, among others, the liquid- vapor equilibrium of
hydrogen at
A. –196 deg °C
B. 196 deg °C
C. 253 deg °C
D. –253 deg °C
Answer: D

168. An open system First Law should be utilized for all of the following EXCEPT
A. a nozzle
B. a turbine
C. a piston-cylinder device with no inlet/exhaust valves
D. a compressor

Answer: C

169. The liquid vapor equilibrium of Oxygen is at what temperature?

A. 197.82 deg °C
B. –197.82 deg °C
C. 182.97 deg °C
D. –182.97 deg °C

Answer: D

170. The solid liquid equilibrium of Mercury is at what temperature?

A. 38.87 deg °C
B. –38.87 deg °C
C. 37.88 deg °C
D. –37.88 deg °C

Answer: B

171. An ideal gas is contained in a rigid container. There is no work of rotating shaft associated
with the container. Any heat transfer is a function of _______.
A. pressure only
B. volume only
C. temperature only
D. there cannot be any heat transfer.

Answer: C

172. The solid - liquid equilibrium of Gold is at what temperature?

A. 630.5 deg °C
B. 960.8 deg °C
C. 1063 deg °C
D. 1774 deg °C

Answer: C

173. The device that measures temperature by the electromotive force.

A. thermometer
B. thermocouple
C. electro-thermometer
D. thermoseebeck

Answer: B

174. The emf is a function of the temperature difference between the junction, a phenomenon
called _______.
A. Seebeck effect
B. Stagnation effect
C. Primming
D. Electromotive force

Answer: A

175. The device that measure temperature by the electromotive force called thermocouple was
discovered by _______.
A. Galileo
B. Fahrenhiet
C. Celsius176.
D. Seebeck

Answer: D

176. When two bodies, solvated 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

177. The total entropy of pure substances 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

178. 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

179. When a certain mass of fluid in a particular state passes through a series of processes and
resumes to its initial state, it undergoes a:
A. revolution
B. rotation
C. process
D. cycle

Answer: D

180. The term given to the collection of matter under consideration enclosed within a boundary.
A. System
B. Matter
C. Environment
D. Atoms

Answer: A

181. 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

182. The true pressure measured above a perfect vacuum.

A. Absolute pressure
B. Gage pressure
C. Atmospheric pressure
D. Vacuum pressure

Answer: A

183. 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

184. The pressure obtained from barometric reading.

A. Absolute pressure
B. Gage pressure
C. Atmospheric pressure
D. Vacuum pressure

Answer: C

185. An adiabatic process is characterized by which of the following?

A. The entropy change is zero
B. The heat transfer is zero
C. It is isothermal
D. The work is zero
Answer: B

186. 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

187. The heat needed by the body is change its phase without changing its temperature
A. Latent heat
B. Sensible heat
C. Specific heat
D. Heat transfer

Answer: A

188. The measure of the randomness of the molecules of substance

A. Enthalpy
8. Internal energy
C. Entropy
D. Heat

Answer: C

189. The heat energy translated to a substance at a constant pressure process is ________.
A. enthalpy
B. heat
C. Internal energy
D. entropy

Answer: A

190. It is the energy stored within the body.

A. Enthalpy
B. Heat
C. Internal energy
D. Entropy

Answer: C

191. 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

192. 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. Charles law
C. Dalton's law
D Avogadro's law

Answer: A

193. 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. Charles law
C. Dalton's law
D. Avogadro's law

Answer: B

194. The pressure exerted in a vessel by a mixture gas is equal to the sum of the pressures that
each separate gas would exert it if it alone occupied the whole volume of the vessel.
A Boyle's law
B. Charles law
C. Dalton's law
D. Avogadro's law

Answer: C
195. At equal volume, at the same temperature and pressure conditions, the gases contain the
same
number of molecules.
A Boyle's law
B. Charle's law
C. Dalton's law
D. Avogadro's law

Answer: D

196. A process in which the system departs from equilibrium state only infinitesimally at every
instant.
A Reversible process
B. Irreversible process
C. Cyclic process
D. Quasi-static process

Answer: D

197. A process which gives the same states/conditions after the system undergoes a series of
processes.
A. Reversible process
B. Irreversible process
C. Cyclic process
D. Quasi-static process

Answer: C

198. 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
199. 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

200. It is a surface that is impervious to heat.

A. isothermal surface
B. adiabatic surface
C. isochoric surface
D. isobaric surface

Answer: B

201. The thermodynamic cycle used in a thermal power plant is

A. Ericsson
B. Brayton
C. Joule
D. Rankine

Answer: D

202. A heat exchange process where in the product pressure and volume remains constant called
_______.
A. heat exchange process
B. isentropic process.
C. throttling process
D. hyperbolic process

Answer: D

203. Which 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

204. Watt is equivalent to ______.

A. 1 N-m/s
B. 1 N-m/min
C. 1 N-m/hr
D. 1 kN-m/hr

Answer: A

205. 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

206. Isentropic flow is _______.

A. perfect gas flow
B. irreversible adiabatic flow
C. ideal fluid flow
D. reversible adiabatic flow

Answer: D

207. At critical point the latent enthalpy of vaporization is ________.

A. dependent on temperature
B. zero
C. minimum
D. maximum

Answer: B

208. 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

209. The end of a substance is the temperatures and pressure at which ________.
A. the solid and 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

210. According to Clausius 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. Heat flows from hot substance to cold substance, unaided and heat can flow from cold
substance
to hot substance with the aid of external work

Answer: D

211. A heat engine is supplied heat at rate of 30,000 J/s gives an output of 9 kW. The thermal
efficiency of the engine is ________.
A 30%
B.43%
C 50%
D. 55%

Answer: A

212. Which of the following cycles has two bothered two constant volume processes?
A Joule cycle
B. Diesel cycle
C. Ericsson cycle
D. Stirling cycle

Answer: D

213. 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

214. 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/(Specific volume at outlet)
C. Temperature of steam at inlet/(Temperature of steam at outlet)
D. None of these

Answer: B

215. A Bell-Coleman cycle is a reversed __________.

A. Stirling cycle
B. Brayton cycle
C. Joule cycle
D. Carnot cycle

Answer: C

216. Ericsson cycle consists of which of the following four processes?

A. two isothermal and two constant volume
B. two isothermal and two constants isentropic
C. two isothermal and two constant pressure
D. two adiabatic and two constant pressure
Answer: C

217. A steam nozzle changes ___________.

A. kinetic energy into heat energy
B. heat energy into potential energy
C. potential energy into heat energy
D. heat energy into kinetic energy

Answer: D

218. 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 temperatures

Answer: D

219. According to Pettlier Thomson effect ___________.

A. It is impossible to construct a heat engine tut 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 tut operates in a cycle and produces no effect other than
the transfer of heat from a cooler body hotter body
C. When two dissimilar metals are heated alone end and cooled at other, e.mt, that is
proportional
to difference of temperature two ends
D. Work can't be converted into heat

Answer: D

220. In actual gases the molecular collisions are

A. plastic
B. elastic
C. inelastic
D. static

Answer: C
221. 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

222. 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

223. 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
224. The vapor pressure is related to the enthalpy of vaporization by the __________.
A. Clausius - Clapeyron's equation
B. Dalton's law
C. Raoult's law
D. Maxwel's equation

Answer: A

225. Solubility of a gas in a liquid at small concentration can be represented by which law?
A. Henry's law
B. Clausius - Clapeyron's equation
C. Dalton's law
D. Roult's law

Answer: A
226. 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

227. 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

228. PAST BOARD QUESTION

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

Answer: B

229. PAST BOARD QUESTION

What is the temperature of a pure substance at a temperature of absolute zero?
A. unity
B. zero
C. infinity
D. 100

Answer: B
230. 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

231. 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

232. 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 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

233. A graph of enthalpy versus entropy for steam.

A. Mollier diagram
B. Moody diagram
C. Steam table
D. Maxwell diagram

Answer: A
234. 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: C

235. 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

236. PAST BOARD QUESTION

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

237. PAST BOARD QUESTION

The Carnot refrigeration cycle includes all of the following process except ________.
A. isentropic expansion
B. isothermal heating
C. isenthalpic expansion
D. isentropic compression

Answer: C

238. PAST BOARD QUESTION

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

239. PAST BOARD QUESTION

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

240. PAST BOARD QUESTION

All of the following terms included in the second law for open system except ____________.
A. shaft work
B. flow work
C. internal energy
D. average work

Answer: D

241. PAST BOARD QUESTION

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

242. PAST BOARD QUESTION

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

243. PAST BOARD QUESTION

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 path between states of thermodynamic equilibrium
D. It represents values of P,V,T and S between states that are path functions

Answer: D

244. A constant pressure thermodynamic process obeys _________.

A. Boyle's law
B. Charles law
C. Amagať's law
D. Dalton's law

Answer: B

245. The first and second laws of thermodynamics are _________.

A. continuity equations
B. momentum equations
C. energy equations
D. equations of state

Answer: C
246. This represents the temperature an ideal gas that will be attained when it is brought to rest
adiabatically.
A. Absolute zero temperature
B. Stagnation temperature
C. Boiling temperature
D. Critical temperature

Answer: B

247. 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

248. 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

249. All of the following are properties of an ideal gas except ___________.
A. density
B. pressure
C. viscosity
D. temperature

Answer: C

250. 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

251. 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. 0ºF and 29.92 in Hg

Answer: D

252. The variation of pressure in an isobaric process is ____________.

A. linear with temperature
B. described by the perfect gas law
C. inversely proportional to temperature
D. zero

Answer: D

253. For fluid flow, the enthalpy is the sum of internal energy and _________.
A. entropy
B. work flow
C. pressure
D. temperature

Answer: B

254. A thermodynamic process whose deviation from equilibrium is infinitesimal at all times is
_________.
A. reversible
B. isentropic
C. in quasi-equilibrium
D. isenthalpic

Answer: C
255. Which thermodynamic property best describes the molecular activity of a substance?
A. Enthalpy
B. Entropy
C. Internal energy
D. External energy

Answer: C

256. Stagnation enthalpy represents the enthalpy of a fluid when it is brought to rest
__________.
A. isometrically
B. adiabatically
C. isothermally
D. disobarically

Answer: B

257. 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

258. 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

259. All of the following are thermodynamic properties except __________.

A. temperature
B. pressure
C. density
D. modulus of elasticity

Answer: D

260. 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

261. A system composed of ice and water at 0°C is sad to be __________.

A. a multiphase material
B. in thermodynamic equilibrium
C. in thermal equilibrium
D. all of these

Answer: D

262. The heat of fusion of a pure substance is __________.

A. the change in phase from solid to gas
B. the change in phase from liquid to gas
C. the energy released in a chemical reaction
D. the energy required to melt the substance

Answer: D

263. 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 from liquid to gas
C. the energy released in a chemical reaction
D. the change in phase from solid to liquid

Answer: B

264. 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 from liquid to gas
C. the energy released in a chemical reaction
D. the change in phase from solid to liquid

Answer: A

265. 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 these

Answer: D

266. 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

267. 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

268. 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

269. Critical properties refer to ___________.

A. extremely important properties, such temperature and pressure as
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

270. 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

271. 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

272. 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
273. The relationship between the total volume of a mixture of non-reacting gases and their
partial
volume is given by_________.
A. gravimetric fractions
B. Amagat's law
C. Dalton's law
D. mole fractions

Answer: B

274. 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

275. 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

276. 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 attractive forces between molecules (eg. 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
277. 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

278. 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

279. All of the following processes are irreversible except_________.

A. Stirring of a viscous fluid
B. An isentropic deceleration of a moving perfect fluid
C. An unrestrained expansion of a gas
D. Phase changes

Answer: B

280. 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

281. 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

282. 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

283. 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

284. PAST BOARD QUESTION

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 closed system plus the entropy change
D. Is equal to the change in total energy of closed system plus net heat transfer

Answer: D

285. PAST BOARD QUESTION

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

286. PAST BOARD QUESTION

Assuming real processes, the net entropy change in the universe_________.
A. must be calculated
B. equals zero
C. is negative
D. is positive

Answer: D

287. PAST BOARD QUESTION

What is referred by control volume?
A. An isolated system
B. Closed system
C. Fixed region in space
D. Reversible process only

Answer: C

288. PAST BOARD QUESTION

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

289. ME BOARD QUESTION

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
290. PAST BOARD QUESTION
Which of the following is used in thermal power plant?
A. Brayton C. Reversed Carnot
B. Rankine D. Otto

Answer: B

291. PAST BOARD QUESTION

A Bell-Coleman cycle is a reversed_________.
A. Stirling cycle C. Joule cycle
B. Carnot cycle D. Otto cycle

Answer: C

292. PAST BOARD QUESTION

The elongation and compression of a helical spring is an example of_________.
A. irreversible process C. reversible process
B. isothermal process D. adiabatic process

Answer: C

293. PAST BOARD QUESTION

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

294. PAST BOARD QUESTION

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 one constant pressure processes
Answer: B

295. PAST BOARD QUESTION

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

296. PAST BOARD QUESTION

The pilot tube is a device used for measurement of_________.
A. Pressure C. Flow
B. Velocity D. Discharge

Answer: B

297. PAST BOARD QUESTION

The continuity equation is applicable to_________.
A. Viscous, unviscous fluids
B. Compressibility of fluids
C. Conservation of mass
D. Steady, unsteady flow

Answer: C

298. PAST BOARD QUESTION

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 =2𝑀𝑉2
B. RL = (1/2) 𝑀𝑉2
C. RL = 2𝑀𝑉
D. RL = (1/2) 𝑀𝑉

Answer: B

299. PAST BOARD QUESTION

Gas being heated at constant volume is undergoing the process of_________.
A. Isentropic C. Adiabatic
B. Isometric D. Isobaric

Answer: B

300. PAST BOARD QUESTION

Dew point is defined as_________.
A. A The temperature to which the air must be cooled at constant pressure to produce saturation
B. The point where the pressure and temperature Iines meet
C. The temperature which dew is formed in the air
D. The pressure which dew is formed in the air

Answer: A

301. PAST BOARD QUESTION

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 pile
C. Atomic transmutation
D. Atomic energy

Answer: C

302. PAST BOARD QUESTION

What do you call the weight of the column of air above the earth's surface?
A. Air pressure
B. Wind pressure
C. Aerostatic pressure
D. Atmospheric pressure

Answer: D

303. PAST BOARD QUESTION

What keeps the moisture from passing through the system?
A. Dehydrator
B. Trap
C. Aerator
D. Humidifier

Answer: A

304. PAST BOARD QUESTION

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

305. PAST BOARD QUESTION

The specific gravity of a substance is the ratio of its density to the density of_________.
A. mercury C. gas
B. air D. water

Answer: D

306. PAST BOARD QUESTION

A compound pressure gauge is used to measure_________.
A. complex pressures
B. variable pressures
C. compound pressures
D. positive and negative pressures

Answer: D

307. PAST BOARD QUESTION

Isentropic flow is_________.
A. A perfect gas flow
B. ideal fluid flow
C. frictionless reversible flow
D. reversible adiabatic flow

Answer: D
308. PAST BOARD QUESTION
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

309. PAST BOARD QUESTION

One Watt is equivalent to____________.
N .m N .m
A. 1 C. 1
s min
N .m k N .m
B. 1 D. 1
hr s

Answer: A

310. PAST BOARD QUESTION

It is the temperature above which a given gas cannot be liquefied.
A. Cryogenic temperature
B. Vaporization temperature
C. Absolute temperature
D. Critical temperature

Answer: D

311. PAST BOARD QUESTION

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

312. PAST BOARD QUESTION

It is the instrument used to measure atmospheric pressure.
A. Rotameter C. Manometer
B. Venturi D. Barometer

Answer: D

313. PAST BOARD QUESTION

Which of the following gases can be used to measure the lowest temperature?
A. Nitrogen C. Helium
B. Oxygen D. Hydrogen

Answer: C

314. PAST BOARD QUESTION

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

315. PAST BOARD QUESTION

Ericsson 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 process
D. Two adiabatic, one constant volume and constant pressure processes

Answer: A

316. PAST BOARD QUESTION

A 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

317. PAST BOARD QUESTION

Which of the following relations 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

318. PAST ME BOARD QUESTION

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

319. PAST BOARD QUESTION

Specific heat capacity is an SI derived unit described as__________.
A. J/kg C. W/m.K
B. kJ/kg.K D. J/m

Answer: B

320. PAST BOARD QUESTION

Which of the following is mathematically a thermodynamic property?
A. A point function C. Discontinuous
B. A path function D. Exact differential

Answer: A

321. PAST BOARD QUESTION

When the expansion or compression of gas takes place "without transfer of heat" to or from the
gas, the process is called__________.
A. reversible C. adiabatic
B. polytropic D. isothermal

Answer: C

322. PAST BOARD QUESTION

A liquid whose temperature is lower than the saturation temperature corresponding to the
existing
pressure:
A. Subcooled liquid C. Saturated liquid
B. Pure liquid D. Compressed liquid

Answer: A

323. PAST BOARD QUESTION

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: D

324. PAST BOARD QUESTION

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

325. PAST BOARD QUESTION

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

326. PAST BOARD QUESTION

What is the area under the curve of a temperature-entropy diagram?
A. Volume C. Heat
B. Work D. Entropy

Answer: C

327. PAST BOARD QUESTION

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 C. Otto cycle
B. Diesel cycle D. Rankine cycle

Answer: A

328. PAST BOARD QUESTION

Both Stirling and Ericson engines are__________.
A. internal combustion engines
B. external combustion engines
C. Carnot engines
D. Brayton engines

Answer: B

329. PAST BOARD QUESTION

Nozzle 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

330. PAST BOARD QUESTION

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. (Ki - Ka) / Ki
C. (Ki - Ka) / Ka
D. Ka / Ki

Answer: D

331. PAST BOARD QUESTION

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

332. 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 pressure__________.
A. dew point
B. ice point
C. boiling point
D. superheated temperature

Answer: C

333. PAST BOARD QUESTION

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
334. PAST BOARD QUESTION
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

335. PAST BOARD QUESTION

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

336. PAST BOARD QUESTION

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

337. PAST BOARD QUESTION

What is the area under the curve of a pressure- volume diagram?
A. Nonflow work
B. Steady flow work
C. Heat
D. Power

Answer: A
338. PAST BOARD QUESTION
In Stirling and Ericson cycle, regeneration can__________.
A. increase efficiency
B. decrease efficiency
C. control efficiency
D. limit efficiency

Answer: A

339. PAST BOARD QUESTION

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

340. PAST BOARD QUESTION

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

341. PAST BOARD QUESTION

At 101.325 kPa, the boiling point of water is 100 °C. If the pressure is decreased, the boiling
temperature will ________.
A. increase C. remain the same
B. decrease D. drop to zero

Answer: C

342. PAST BOARD QUESTION

Which of the following is equivalent to 1 hp in Btu/hr?
A. 778 C. 2545
B. 746 D. 3.41

Answer: C

343. PAST BOARD QUESTION

What is the pressure above zero?
A. Gage pressure C. Absolute pressure
B. Vacuum pressure D. Atmospheric pressure

Answer: A

344. PAST BOARD QUESTION

Which of the following is the instrument used to measure fluid velocity?
A. Pitot tube C. Orsat apparatus
B. Anemometer D. Viscosimeter

Answer: A

345. PAST BOARD QUESTION

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

346. PAST BOARD QUESTION

The true pressure measured above a perfect vacuum is__________.
A. absolute pressure
B. atmospheric pressure
C. gauge pressure
D. vacuum pressure

Answer: A
347. PAST BOARD QUESTION
If an initial volume of an ideal gas is compressed to one half its original volume and to twice its
original temperature, the pressure:
A. doubles
B. halves
C. quadruples
D. triples

Answer: C

348. PAST BOARD QUESTION

As the air passes through the diffuser, which of the following will not be affected?
A. entropy
B. density
C. velocity
D. Mach number

Answer: A

349. PAST BOARD QUESTION

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

Answer: D

350. PAST BOARD QUESTION

This form of energy is due to the position or elevation of the body.
A. internal energy
B. kinetic energy
C. potential energy
D. work

Answer: C
CHAPTER 2 - FUELS & COMBUSTION
1. PAST BOARD QUESTION
Which is not a viscosity rating?
A. Redwood
B. SSU
C. Centipoise
D. Entropy Degrees API

Answer: D

2. PAST BOARD QUESTION

Percent excess air is the difference between the air actually supplied and the theoretically
required divided by__________.
A. the theoretically air supplied
B. the actually air supplied
C. the deficiency of air supplied
D. the sufficient air supplied

Answer: A

3. PAST BOARD QUESTION

What is the apparatus used in the analysis of combustible gases?
A. Calorimeter differential
B. Calorimeter gas
C. Calorimetry
D. Calorimeter

Answer: D

4. PAST BOARD QUESTION

Percent excess air is the difference between the air actually supplied and the theoretical air
divided by
A. the sufficient air supplied
B. the deficiency air supplied
C. the actually air supplied
D. the theoretically air supplied

Answer: D
5. PAST BOARD QUESTION
The viscosity of most commercially available petroleum lubricating oil changes rapidly
above__________.
A. 120 °F
B. 180 °F
C. 150 °F
D. 130 °F

Answer: B

6. PAST BOARD QUESTION

When 1 mol carbon combines with 1 mol oxygen
A. 2 mols carbon dioxide
B. 1 mol carbon dioxide
C. 1 mol carbon and 1 mol carbon dioxide
D. 1 mol carbon dioxide

Answer: B

7. PAST BOARD QUESTION

What are the immediate undesirable products from the petroleum based lubricating oil when
subjected to high pressure and temperature?
A. Gums, resins and acids
B. Sulfur
C. Soots and ashes
D. Carbon residue
Answer: A

8. PAST BOARD QUESTION

What fuel is used in a power plant during peak periods?
A. Gas
B. Liquid
C. Solid
D. Nuclear

Answer: B
. PAST BOARD QUESTION
Which of the following gases is produced by the combustion of fuel oil and cannot be found in
the flue gases?
A. carbon dioxide
B. hydrogen
C. oxygen
D. nitrogen

Answer: B

9. PAST BOARD QUESTION

The fuel injection process in diesel engine starts when the piston _______.
A. Is at the TDC
B. Approaches TDC
C. Leaves TDC
D. Halfway of the stroke

Answer: B

10. PAST BOARD QUESTION

What is the typical compression ratio of Otto cycle?
A. 6
B. 10
C. 8
D. 12

Answer: C

11. PAST BOARD QUESTION

Oil is atomized either by air blast or pressure jet at about _________.
A. 60 bar
B. 70 bar
C. 80 bar
D. 50 bar

Answer: B

12. PAST BOARD QUESTION

Which of the following is the type of solid injection that uses single pump to supply fuel under
high pressure to a fuel header?
A. Common rail injection
B. Individual pump injection system
C. Distributor system
D. Single rail injection

Answer: A

13. PAST BOARD QUESTION

It is known as the cooling where water flow in diesel engine due to its density differential.
A. Thermosiphon cooling
B. Thermostat cooling
C. Pressurized water cooling
D. Evaporative water cooling

Answer: A

14. PAST BOARD QUESTION

Type of lubrication system in diesel engine in which oil from pump is carried to a separate
storage tank outside the engine cylinder and used for high-capacity engine.
A. Mist lubrication system
B. Wet sump lubrication system
C. Splash lubrication system
D. Dry sump lubrication system

Answer: D

15. PAST BOARD QUESTION

Which of the following produces extreme pressure differentials and violent gas vibration?
A. Vibration
B. Detonation
C. Explosion
D. Knocking

Answer: B

16. PAST BOARD QUESTION

In a spark ignition engine, the detonation occurs near the _________.
A. End of combustion
B. Middle of combustion
C. Beginning of combustion
D. Beginning of compression

Answer: A

17. PAST BOARD QUESTION

In a compression ignition engine, the detonation occurs near the _________.
A. End of combustion
B. Middle of combustion
C. Beginning of combustion
D. Middle of interaction

Answer: C

18. PAST BOARD QUESTION

Loss power is due to ________.
A. Poor compression
B. Restricted exhaust
C. Clogging of air cleaner
D. Low injection pressure

Answer: D

19. PAST BOARD QUESTION

How do you call a branch system of pipes to carry waste emissions away from the piston
chambers of an internal combustion engine?
A. Exhaust nozzle
B. Exhaust deflection pipe
C. Exhaust pipe
D. Exhaust manifold

Answer: D

20. PAST BOARD QUESTION

The type of filter where the filtering elements is replaceable.
A. Paper edge filter
B. Metal edge filter
C. Pressure filter
D. Filter with element

Answer: B

21. PAST BOARD QUESTION

When four events takes place in one revolution of a crankshaft of an engine, the engine is called
_________.
A. Rotary engine
B. Steam engine
C. Two stroke engine
D. Four stroke engine

Answer: C

22. PAST BOARD QUESTION

Which of the following does not belong to the group?
A. Air injection system
B. Mechanical injection system
C. Time injection system
D. Gas admission system

Answer: C

23. PAST BOARD QUESTION

The internal combustion engines never work in _________.
A. Rankine cycle
B. Diesel cycle
C. Dual combustion cycle
D. Otto cycle

Answer: A

24. PAST BOARD QUESTION

The thermal efficiency of an ideal Otto cycle depends on __________.
A. the pressure ratio of the engine and the specific heat ratio of the working fluid the engine and
the specific
B. the temperature ratio of heat ratio of the working fluid
C. the moles ratio of the engine and the temperature of the working fluid
D. the compression ratio of the engine and the specific heat ratio of the working fluid

Answer: D

25. PAST BOARD QUESTION

If monatomic gas is used, what will happen to the thermal efficiency of Otto cycle?
A. increases
B. decreases
C. Remains constant
D. Nothing happens

Answer: A

26. PAST BOARD QUESTION

In diesel engine, combustion process occurs during what process? of the following is lowest
grade of coal?
A. isothermal process
B. constant pressure process
C. isentropic process
D. adiabatic process

Answer: B

27. PAST BOARD QUESTION

What air pressure is needed for air starting a diesel engine?
A. 350 psi
B. 250 psi
C. 450 psi
D. 150 psi

Answer: B

28. PAST BOARD QUESTION

Mechanical energy of pressure transformed into energy of heat
A. Kinetic energy
B. Enthalpy
C. Heat exchanger
D. Heat of compression

Answer: B

29. PAST BOARD QUESTION

Ignition of the air fuel mixture in the intake of the exhaust manifold.
A. Backlash
B. Backfire
C. Exhaust pressure
D. Back pressure

Answer: B

30. PAST BOARD QUESTION

The total sulfur content in a diesel fuel must not exceed ________.
A. 0.3%
B. 0.5%
C. 0.8%
D. 0.11%

Answer: B

31. PAST BOARD QUESTION

When crude oil is heated, then which one of the following hydrocarbon is given off first?
A. Gasoline
B. Paraffin
C. Diesel
D. Natural gas

Answer: D

32. PAST BOARD QUESTION

The color of lubricating oil _________.
A. does not indicate contamination.
B. does not indicate qualities
C. indicates qualities
D. indicates viscosity

Answer: A

33. PAST BOARD QUESTION

If the cutoff ratio decreases, what will happen to the efficiency of diesel cycle?
A. Increases
B. Decreases
C. Remains constant
D. Slightly decreases

Answer: C

34. PAST BOARD QUESTION

During a combustion process, how do you call the components which exist before the reaction?
A. Reaction
B. Combustion
C. Reactants
D. Product of combustion

Answer: C

35. PAST BOARD QUESTION

Which of the following is an obvious reason for incomplete combustion?
A. insufficient carbon
B. insufficient air
C. insufficient nitrogen and hydrogen
D. insufficient oxygen

Answer: D

36. PAST BOARD QUESTION

Which of the following is the chemical formula for Heptane?
A. C7H16
B. C2H2O
C. C4H
D. C8H12
Answer: A

37. PAST BOARD QUESTION

Enthalpy of substance at specified state due to chemical composition.
A. Enthalpy of reaction
B. Enthalpy of combustion
C. Enthalpy of formation
D. Enthalpy of product

Answer: C

38. PAST BOARD QUESTION

There are two broad types in the classification of lubricating oils, these are straight
and__________.
A. Active
B. Inactive
C. Crooked
D. Additives

Answer: D

39. PAST BOARD QUESTION

Most commercially available petroleum lubricating oil deteriorates starting from what operating
temperature?
A. 150 °F
B. 200 °F
C. 300 °F
D. 250 °F

Answer: B

40. PAST BOARD QUESTION

An Orsat apparatus is used for _________.
A. Volumetric analysis of the flue gases
B. Gravimetric analysis of the flue gases
C. Smoke density analysis of the gases
D. All of these
Answer: A

41. PAST BOARD QUESTION

This is the indicator used to determine the anti-knock characteristics of gasoline.
A. Anline point
B. Cetane number
C. Octane number
D. Diesel index

Answer: C

42. PAST BOARD QUESTION

Amount of heat liberated by the complete combustion of a unit weight or volume of fuel is
__________.
A. Heating value
B. Latent heat
C. Sensible heat
D. Work of compression

Answer: A

43. PAST BOARD QUESTION

Which of the following is the chemical formula for Ethanol?
A. C7H16
B. C7H18
C. C2H6O
D. C8H16

Answer: C

44. PAST BOARD QUESTION

Which of the following is true?
A. The ignition of a diesel fuel can be improved by the addition of small percentage of more
easily
ignitable hydrocarbons
B. The ignition quality of a gasoline fuel measured by an index called cetane number
C. The ignition quality of a diesel engine is measured by an index called octane number
D. None of these

Answer: A

45. PAST BOARD QUESTION

Which of the following is the chemical formula for Hexene?
A. C7H16
B. C7H18
C. C2H6O
D. C6H12

Answer: D

46. PAST BOARD QUESTION

Higher heating value of fuel is determined when H₂O in the product of combustion is in
_________.
A. Solid form
B. Vapor form
C. Gaseous form
D. Liquid form

Answer: D

47. PAST BOARD QUESTION

Which of the following is the chemical formula for Toluene?
A. C4H16
B. C2H6O
C. C7H8
D. C8H16

Answer: C

48. PAST BOARD QUESTION

Air that controls the rate of combustion in the combustion chamber is known as _________.
A. Secondary air
B. Excess air
C. Control air
D. primary air
Answer: A

49. PAST BOARD QUESTION

Percentage of excess air is the difference between the air actually supplied and the theoretically
required divided by _________.
A. actual air supplied
B. theoretical air supplied
C. theoretical less actual supplied
D. deficient air supplied

Answer: B

50. PAST BOARD QUESTION

When fuel oil has a high viscosity then the fuel oil _________.
A. will evaporate easily
B. will have a low specific gravity
C. will burn without smoke
D. will flow slowly through pipes

Answer: D

51. PAST BOARD QUESTION

Engines using heavy fuels require heating of the fuel so that the viscosity at the injector is
_________.
A. around 200 SSU
B. 100 SSU or less
C. 200 SSU + 50
D. 150 SSU or slightly higher

Answer: D

52. PAST BOARD QUESTION

Which of the following gases is produced by the combustion of fuel oil and cannot be found in
the flue gases?
A. carbon dioxide
B. hydrogen
C. oxygen
D. nitrogen

Answer: B

53. PAST BOARD QUESTION

Amount of heat liberated by the complete combustion of a unit weight of volume of fuel is
________.
A. heating value
B. latent heat
C. sensible heat
D. work of compression

Answer: A

54. PAST BOARD QUESTION

These are the products of complete combustion of gaseous hydrocarbons.
A. Carbon dioxide and water
B. Carbon monoxide
C. Carbon monoxide, water and ammonia
D. Water, carbon monoxide and carbon dioxide

Answer: A

55. PAST BOARD QUESTION

When the water in the products of combustion is in the vapor state, the heating value is called
_________.
A. lower heating value
B. higher heating value
C. gross calorific value
D. average heating value

Answer: A

56. PAST BOARD QUESTION

At what temperature wherein an oil of any grade becomes cloudy and it freezes, thus; its
application is limited.
A. Cold point
B. Flash point
C. Pour point
D. Freezing point

Answer: A

57. PAST BOARD QUESTION

Dry air can be approximated as ___% oxygen and ___% and ___% nitrogen by mole numbers.
A. 30% and 70%
B. 70% and 30%
C. 21% and 79%
D. 79% and 21%

Answer: C

58. PAST BOARD QUESTION

This is the lowest temperature to which an oil must be heated in order to give off inflammable
vapors in a sufficient amount to momentarily ignite when brought in contact with a flame.
A. pour point
B. fire point
C. flash point
D. torch point

Answer: C

59. PAST BOARD QUESTION

Which of the following is the gas produced in the combustion of fuel oil and cannot be found in
the flue gasses?
A. oxygen
B. hydrogen
C. carbon dioxide
D. nitrogen

Answer: B

60. PAST BOARD QUESTION

Which of the following petroleum distillate having a flashpoint not below 22.8℃?
A. Kerosene
B. Alcohol
C. Gasoline
D. Diesel

Answer: A

61. PAST BOARD QUESTION

Which of the following properties that influence the performance and reliability of diesel fuel?
A. Volatility
B. Carbon residue
C. Viscosity
D. All of these

Answer: D

62. PAST BOARD QUESTION

The processes by which the mixture of oil and water does not separate into its components, (i.e.
oil and water).
A. mixture
B. suspension
C. emulsion
D. coagulation

Answer: C

63. PAST BOARD QUESTION

When H2O in the products of combustion is in liquid form, the heating value is known as
_________.
A. higher heating value
B. lower heating value
C. low and medium heating value
D. average heating value

Answer: A

64. PAST BOARD QUESTION

This is the flow of fluids wherein its particles do not have definite paths and the paths of the
individual and distinct particles cress one another.
A. Non-uniform flow
B. Unsteady flow
C. Laminar flow
D. Turbulent flow

Answer: D

65. PAST BOARD QUESTION

If the composition of hydrocarbon fuel is known, the ratio between the nitrogen and oxygen that
is supplied in air is _________.
A. equal
B. constant
C. intensity
D. fixed

Answer: B

66. PAST BOARD QUESTION

This is the property of liquid by which it extends resistance to angular or shear deformation.
A. specific gravity
B. specific weight
C. viscosity
D. density

Answer: C

67. PAST BOARD QUESTION

A property of lubricating oil that measures the thickness of the oil and will help determine how
long oil will flow at a given temperature is known as ________.
A. viscosity
B. flash point
C. cloud point
D. pour point

Answer: A

68. PAST BOARD QUESTION

How do you call the time by which it takes to heat the fuel particles, turn them into vapor, and
start combustion?
A. ignition delay
B. lag time
C. recuperation
D. pre-ignition time

Answer: A

69. PAST BOARD QUESTION

This is the type of coal formed after anthracite.
A. Lignite
B. Bituminous
C. Peat
D. Graphite

Answer: D

70. PAST BOARD QUESTION

Which of the following is lowest grade of coal?
A. Peat
B. Lignite
C. Sub-bituminous
D. Bituminous coke

Answer: B

71. PAST BOARD QUESTION

Which of the following helps in the ignition of coal?
A. moisture of vapor
B. ash
C. fixed carbon
D. volatile matter

Answer: D

72. PAST BOARD QUESTION

What is the ratio of fixed carbon and volatile matter?
A. air-fuel ratio
B. fuel ratio
C. combustion ratio
D. carbon-volatile ratio

Answer: B

73. PAST BOARD QUESTION

It is the suspension of a finely divide fluid in another.
A. filtration
B. emulsion
C. floatation
D. separation

Answer: B

74. PAST BOARD QUESTION

Which of the following contains 90% gasoline and 10% ethanol.
A. Gasohol
B. Gasonol
C. Gasothanol
D. Gasethanol

Answer: A

75. PAST BOARD QUESTION

Which of the following is the process used commercially in coal liquefaction?
A. Tropsch process
B. Fischer process
C. Fischer-Tropsch process
D. Mixed-Tropsch process

Answer: C

76. PAST BOARD QUESTION

Which of the following is an organic matter produced by plants in both land and water?
A. Bio-ethanol
B. Biomass
C. Petroleum
D. Biodegradable
Answer: B

77. PAST BOARD QUESTION

The minimum amount of air required for a complete combustion of fuel is called ______.
A. dry air
B. excess air
C. theoretical air
D. flue gas

Answer: C

78. PAST BOARD QUESTION

The temperature at which lubricating will form a cloud.
A. Cloud point
B. Pour point
C. Critical point
D. Boiling point

Answer: A

79. PAST BOARD QUESTION

The ideal cycle based on the concept that the combustion process is both diesel and gasoline in
the combination of heat transfer processes that is constant pressure and constant volume.
A. Ericsson cycle
B. Dual cycle
C. Brayton cycle
D. Rankine cycle

Answer: B

80. PAST BOARD QUESTION

It is the average pressure on a surface when a changing pressure condition exisit.
A. back pressure
B. partial pressure
C. pressure drop
D. mean effective pressure
Answer: D

81. PAST BOARD QUESTION

What is the distance between TDC and BDC in which the piston can travel?
A. right extreme position
B. displacement stroke
C. stroke of the engine
D. swept stroke

Answer: C

82. PAST BOARD QUESTION

In compression-engine, the combustion of air-fuel mixture is self-ignited as a result of
compressing the mixture above its ______.
A. self developed temperature
B. mixing temperature
C. self-sustaining fed temperature
D. self ignition temperature

Answer: D

83. PAST BOARD QUESTION

Morse test is used to measure the _______ of multi-cylinder engine.
A. Brake power
B. Indicated power
C. Friction Power
D. Motor power loss

Answer: B

84. PAST BOARD QUESTION

Ignition delay can be minimized by adding _____ to decrease engine knocking.
A. Ethel ether
B. Ethyl chloride
C. Ethyl nitrate
D. Ethyl dioxide

Answer: C
85. PAST BOARD QUESTION
What is the largest group of coal containing 46-86% of fixed carbon and 20 to 40% volatile
matter?
A. Anthracite
B. Sub-anthracite
C. Bituminous
D. Sub-bituminous

Answer: C

86. PAST BOARD QUESTION

When 1 gram of coal is subjected to a temperature of about 105 ℃ for a period of 1 hour, the loss
in weight of sample gives the __________.
A. volatile matter
B. ash and sulfur
C. fixed carbon
D. moisture content

Answer: D

87. PAST BOARD QUESTION

When 1 gram of sample of coal is placed in a crucible and heated 950 ℃ and maintain at that
temperature for 7 minutes there is a loss in weight due to elimination of which of the following?
A. volatile matter and moisture
B. ash
C. fixed carbon and sulfur
D. moisture content

Answer: A

88. PAST BOARD QUESTION

Which of the following that consists of hydrogen and certain hydrogen carbon compounds which
can be removed from coal by heating?
A. Moisture content
B. Product of combustion
C. Ash
D. volatile matter
Answer: D

89. PAST BOARD QUESTION

Which of the following will be formed by heating 1 gram of coal in an uncovered crucible until
the coal is completely burned?
A. volatile matter
B. Ash
C. Fixed carbon
D. moisture content

Answer: B

90. PAST BOARD QUESTION

Caking coal are used to produce coke by heating in a coke oven in the absence of _______ with
volatile matter driven off.
A. Air C. oil and Sulfur
B. Oxygen D. Nitrogen

Answer: A

91. PAST BOARD QUESTION

What is the grindability of standard coal?
A. 80 C. 90
B. 100 D. 110

Answer: B

92. PAST BOARD QUESTION

What is the major constituent of all natural gases?
A. ethane C. methane
B. propane D. pentane

Answer: C

93. The general chemical formula for all hydrocarbons is C nHm in different combinations of
interest, as internal combustion engine fuel, n varies from _________.
A. 1 to 26
B. 2 to 26
C. 2 to 54
D. 1 to 54

Answer: A

94. The general chemical formula for all hydrocarbons is C nHm. In different combinations of
interest, as internal combustion engine fuel m varies from:
A. 1 to 26
B. 2 to 26
C. 2 to 54
D. 1 to 54

Answer: C

95. The general chemical formula of a paraffin fuel is

A. CnH2n
B. CnH2n-6
C. CnH2n+6
D. CnH2n-2

Answer: C

96. Which of the following types of hydrocarbons have chemical formula of CnH2n-2?
A. Diolefins
B. Aromatics
C. Asphaltics
D. Paraffins

Answer: A

97. Which of the following types of hydrocarbons have chemical formula of CnH2n-4?
A. Diolefins
B. Aromatics
C. Asphaltics
D. Paraffins

Answer: C
98. What is the chemical formula of an Aromatic type of hydrocarbon fuels?
A. CnH2n-6
B. CnH2n
C. CnH2n-2
D. CnH2n+2

Answer: A

99. At atmospheric condition, hydrocarbon molecules with a low number of carbon atoms, 1 to 4
are
A Liquids
B. Gases
C. Atomic
D. Light oils

Answer: B

100. Hydrocarbons with 5 to 15 carbon atoms are

A. more or less volatile light oils
B. referred to as heavy oils
C. mixtures of many kinds of hydrocarbons
D. commercial fuels

Answer: A

101. Hydrocarbons with 16 to 26 carbon atoms are referred to as

A. light oils
B. commercial fuels
C. heavy oils
D. lubricating oils

Answer: C

102. In a four-stroke engine if a valve opens 25° before B.D.C. and close 10° after T.D.C. the
valve should be
A. puppet valve
B. inlet valve
C. exhaust valve
D. spring valve

Answer: C

103. Sticking valves are:

A. valve tappet clearance incorrect
B. valve springs of defective material
C. valve guides gummed
D. lubricating oil of poor quality

Answer: B

104. Detonation of pinging noise is due to:

A. early timing of fuel injection
B. late timing of fuel injection
C. head of piston carbonized
D. valve springs weak or broken

Answer: B

105. Scavenging efficiency of a four-stroke diesel engine is:

A. in the range 80 - 95 percent
B. in the range 60-80 percent
C. below 60 percent
D between 95% and 100%

Answer: D

106. Volumetric efficiency of a well-designed engine may be in the range of

A. 75 to 90 percent
B. 30 to 50 percent
C. 60 to 75 percent
D. below 30 percent

Answer: A
107. During idling in a compression ignition engine the air fuel ratio may be of the order of
A. 30
B. 150
C. 200
D. 100

Answer: A

108. Vapor lock is:

A. lock of vaporization of fuel to atmospheric pressure
B. excess fuel supply to engine because of faster evaporation
C. complete or partial stoppage of fuel supply because of vaporization of fuel in supply steam
D. locking carburetor jets because of vapor pressure

Answer: C

109. Flash point of liquids is the temperature at which _________.

A. the fuel emits vapors at a rate which produces an inflammable mixture with air
B. the fuel spontaneously ignites
C. the fuel ignites with clearly visible flash
D. the fuel ignites without a spark

Answer: A

110. The mean effective pressure of a diesel cycle having fixed compression ratio will increase if
cut off ratio is _________.
A. increased
B. decreased
C. independent of compression ratio
D. depends on other factor

Answer: A

111. Flash point for diesel fuel oil should be

A. maximum 49 °C
B. maximum 490 °C
C. maximum 200 °C
D. maximum 300 °C
Answer: A

112. Morse test is conducted on _________.

A. single-cylinder engines
B. multi-cylinder engines
C. horizontal engines
D. vertical engines

Answer: B

113. Prony brake is used for testing of ________.

A. small engines
B. large engines
C. engines having small flywheel
D. high speed engines

Answer A

114. Clog point of an oil refer to __________.

A. the point of maximum contamination of oil
B. the level of impurities beyond which oil ceases to flow
C. the temperature at which oil solidifies
D. the temperature at which paraffin and waxes in oil start precipitating

Answer: D

115. Otto cycle consists of __________.

A two isentropic and two constant volumes 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

116. Diesel cycle consists of __________.

A. isentropic, isothermal, constant volume, constant pressure process
B. two constant volume, one constant pressure, and one isothermal process
C. Iwo one constant volume and one constant pressure processes
D. two constant pressure, one constant volume, and one isentropic process

Answer: C

117. 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 temperatures

Answer: D

118. For balancing single cylinder engine a counter weight is added to

A. piston
B. cam
C. piston pin
D. crank

Answer. D

119. To measure the clearance between the valve and tappet of an automobile engine we use a
_________.
A. Vernier scale
B. pneumatic gauge
C. feeler gauge
D. slip gauge

Answer: C

120. By supercharging _________.

A. power stroke becomes stronger
B. loss in exhaust gets reduced
C. engine can be made to run smoother
D. thermal efficiency of the engine can be improved

Answer: D
121. Speedometer drive is generally taken from __________.
A. dynamo
B. fan belt
C. flywheel
D. front wheel

Answer: D

122. Odometer is __________.

A. an instrument that indicates the condition of the battery
B. an instrument used for measurement of fuel consumption
C. an instrument used for BHP measurement
D. an instrument used for distance measurement

Answer: D

123. Automobile radiator is filled with _________.

A. acidic water
B. hard water
C. alkaline water
D. soft water

Answer: D

124. The ignition coil acts as _________.

A. a capacitor
B. an RC circuit
C. an inductor
D. a step-up transformer

Answer: D

125. The self-starting motor for automobiles is a __________.

A. universal motor
B. DC series motor
C. DC shunt motor
D. synchronous motor
Answer: B

126. Starting motor current may be about _________.

A. 0.15 A
B. 5.1 A
C. 0.5 A
D. 25 A

Answer: D

127. As a rule before the piston are removed, it is essential to remove the ________.
A. gudgeon pin
B. piston rings
C. circlip
D. crankshaft

Answer: B

128. Common causes for excessive oil consumption include __________.

A. heavy oil and light bearings
B. high speed and worn engine
C. short trips and cold weather
D. frequent oil changes

Answer: B

129. The device that is used for reducing the exhaust noise is called _________.
A. exhaust manifold
B. muffler
C. exhaust pipe
D. none of the above

Answer: B

130. The device that is used to measure the clearance between the valve and tappet of an internal
combustion engine is measured by using ________.
A. snap gauge
B. feeler gauge
C. slip gauge
D. micrometer

Answer: B

131. Which of the following instrument is used in measuring specific gravity?

A. Thermometer
B. Anemometer
C. Hygrometer
D. Hydrometer

Answer: D

132. Exhaust gas leakage into the cooling system is most likely to occur because of defective:
A. cylinder head gasket
B. water pump
C. manifold gasket
D. any of these

Answer: A

133. Clutch slippage while clutch is engaged is especially noticeable __________.

A. during idling
B. during acceleration
C. at low speed
D. during braking

Answer: B

134. Latex is _____________.

A. a plastic
B. a cover on writes carrying current to spark plugs
C. a variety of lubricant
D. a milky juice of rubber

Answer: D

135. The Diesel fuel pump is designed to supply fuel _________.

A. just sufficient against the demand of the injection pump
B. in excess quantity than needed by the injection pump
C. a constant quantity at all engine speeds
D. insufficient quantity in accordance with the engine speed

Answer: D

136. The fuel is injected into the cylinder in Diesel engine when the piston is __________.
A. exactly at B.D.C. after compression stroke
B. exactly at T.D.C. before compression stroke
C. approaching T.D.C. during compression stroke
D. approaching B.D.C. during exhaust stroke

Answer: C

137. Dirt or gum in fuel nozzle or jets can produce __________.

A. excessive fuel consumption
B. lack of engine power
C. smoky black exhaust
D. white exhaust

Answer: C

138. Oil pan is attached _________.

A. to the bottom of the cylinder block
B. in a separate unit away from the crankcase
C. at the top of the cylinder block D. at the outside wall of the crank case
D. at the outside wall of the crank case

Answer: A

139. Excess oil consumption in engine may be because of __________.

A. leakage of oil through oil pan gasket
B. poor quality or improper viscosity of engine oil
C. excessive oil pressure
D. any of these

Answer: D
140. Wheel base of a vehicle is the __________.
A. distance between front and rear axles
B. distance between the front tires
C. extreme length of the vehicle
D. width of tires

Answer: A

141. The percentage of heat released from fuel-air mixture, in an internal combustion engine
which is converted into useful work is roughly __________.
A. 10 per cent
B. 20-25 per cent
C. 10-20 per cent
D. 40-45 per cent

Answer: B

142. The efficiency of hydraulic braking system is ________.

A. about 90 percent
B. 50-60 percent
C. 60-80 percent
D. 40-50 percent

Answer: A

143. The instrument that is used to check the state of charge of a battery is called a _________.
A. hydrometer
B. battery eliminator
C. battery charger
D. anemometer

Answer: A

144. When not in use, the self-discharge of an automobile battery in dry weather is generally
_________.
A. 0.5 to 1%
B. 5 to 7.5%
C. 3 to 5%
D. not more than 10%

Answer: A

145. A spark voltage requires a voltage of __________.

A. 112 V
B. 220 V
C. 124 V
D. 440 V

Answer: B

146. The minimum cranking speed in petrol engine is __________.

A. same as the normal operating speed
B. half of operating speed
C. one fourth of operating speed
D. 60-80 rpm

Answer: D

147. Which oil is more viscous?

A. SAE 30
B. SAE 80
C. SAE 50
D. SAE 40

Answer: B

148. Engine oil is generally changed after ___________.

A. 100 km C. 1500 km
B. 1100 km D. 2500-6000 km

Answer: D

149. In a vehicle the most probable cause for hard steering may be _____________.
A. low tire pressure C. bent wheel spindle
B. tie rod ends tight D. any of the above
Answer: D

150. Poor compression in a two-stroke engine cannot be because of ______________.

A. leaky valves
B. broken piston rings
C. leaking cylinder head gasket
D. poor fits between pistons, rings and cylinder

Answer: A

151. The number of exhaust manifolds in a V-8 engine is _________.

A. one
B. four
C. there is no exhaust manifold
D. two

Answer: D

152. The device for smoothing out the power impulses from the engine is known as _________.
A. clutch C. fly wheel
B. gear box D. differential

Answer: C

153. The firing order in case of four cylinder in - line engines is generally
A. 1-2-4-3
B. 1-3-4-2
C. 1-4-3-2
D. either 1-3-4-2 or 1-4-3-2

Answer: D

154. In case of four cylinder opposed cylinder engines, the firing order is
A. 1-4-3-2 C. 1-3-4-2
B. 1-2-3-4 D. 1-2-4-3

Answer: A
155. In a four-stroke engine, for the combustion of one liter of fuel, the volume of air needed
would
approximately be _________.
A. 1 m^3 C. 2 m^3
B. 5-7 m^3 D. 9-10 m^3

Answer: D

156. Theoretically air needed for the combustion of one kg of fuel is

A. 100 kg C. 14.5 kg
B. 16.7 kg D. 27.4 kg

Answer: C

157. Which of the following is the cause of loss power?

A. Poor compression
B. Restricted exhaust
C. Clogging of air cleaner
D. Low injection pressure

Answer: D

158. A valve in the carburetor of an internal combustion engines which regulates the proportion
of
air gasoline vapors entering the cylinder.
A. Gate valve C. Choke valve
B. Check valve D. Globe valve

Answer: C

159. What device combines air and fuel for burning in cylinder?
A. Intercooler C. Regenerator
B. Fuel injection D. Carburetor

Answer: D

160. In Stirling engine, the heat is added during

A. isothermal process
B. isometric process
C. isobaric process
D. isentropic process

Answer: A

161. In an Otto engine, the heat is added during

A. isothermal process C. isometric process
B. isobaric process D. isentropic process

Answer: C

162. Exhaust stroke of gasoline engine is also known as ______________.

A. Supercharging C. choking
B. scavenging D. knocking

Answer: B

163. The mechanical efficiency of a device is the ratio of the ____________

A. mechanical energy input to the mechanical energy output of the device
B. energy input to the actual energy input
C. actual energy extracted to the ideal energy extracted
D. actual to the ideal energy input

Answer: B

164. The smallest subdivision of an element that can take place in a chemical reaction is a/an
__________.
A. atom C. molecule
B. electron D. proton

Answer: A

165. The smallest subdivision of a compound that can exist in a natural state is a/an
____________.
A. atom C. molecule
B. electron D. proton
Answer: C

166. How do you call the elements with different atomic weights but the same atomic number?
A. Isomers C. isotropes
B. isotopes D. isobars

Answer: B

167. All of the following are characteristics of metals except _________.

A. high electrical conductivities
B. tendency to form positive ions
C. tendency to form brittle solids
D. high melting points

Answer: C

168. The following are all characteristics of nonmetals except __________.

A. having little or no luster
B. appearing on the right end of the periods table
C. having low ductility
D. being reducing agents

Answer: D

169. All of the following are components of a chemical elements except ___________.
A. protons C. neutrons
B. electrons D. ions

Answer: D

170. Which of the following is not a prefix used in naming isomers?

A. Para C. Meta
B. Cis D. Bi

Answer: D

171. All of the following are types of chemical bonds except ___________.
A. ionic bonds C. covalent bonds
B. metallic bonds D. nuclear bonds

Answer: D

172. The equilibrium distance between elements in an ionic bond is function of all the following
except:
A. ionic charge C. coordination number
B. atomic weight D. temperature

Answer: B

173. Which of the following statements is not a characteristic of ionic compounds?

A. They are usually hard, brittle, crystalline solids
B. They have high melting points
C. They are nonvolatile and have low vapor pressures
D. They are good electrical conductors in the solid phase

Answer: D

174. What kind of bonding do common gases that exist in a free state as diatomic molecules
experience?
A. lonic bonds C. Covalent bonds
B. Metallic bonds D. Nuclear bonds

Answer: C

175. Measure the diffuser's ability to increase the pressure of the fluid is ___________.
A. speed recovery factor
B. pressure recovery factor
C. volume recovery factor
D. diffuser recovery factor

Answer: B

176. What is the main power generating plant that produces the most electricity per unit thermal
energy in the fuel input and has the greatest surplus of electricity for most cogeneration system?
A. Steam engine C. Steam turbine
B. Gas turbine D. Diesel engine

Answer: D

177. Air standard efficiency of a diesel engine depends on ___________.

A. Speed C. compression ratio
B. fuel D. torque

Answer: C

178. What is meant by brake horsepower?

A. Power developed in the engine cylinder
B. Final horsepower delivered to the equipment
C. Actual horsepower delivered to the engine drive shaft
D. Work required to raise a weight of 33,000 lbs at a height of one foot in one minute of time.

Answer: C

179. The unit used for expressing API gravity is _________.

A. gm/cc C. dimensionless numbers
B. degrees D. none of the above

Answer: B

180. ASTM coal classification is based on __________.

A. proximate analysis C. orsat analysis
B. ultimate analysis D. none of the above

Answer: A

181. API gravity of water is ___________.

A. zero C. 10
B. 1.0 D.100

Answer: C

182. Which of the following variety of coal has highest ash content?
A. Lignite C. Bituminous coal
B. Grade I steam coal D. Coking coal

Answer: A

183. Which of the following is a petroleum fuel?

A. Benzol C. Ethyl alcohol
B. Methyl alcohol D. Naphta

Answer: D

184. Diesel engine fuels are rated by ______________.

A. specific gravity C. calorific value
B. cetane number D. octane number

Answer: B

185. Which of the following needs to be filtered in a diesel engine?

A. Air only C. Lubricating oil only
B. Air and diesel oil only D. Air, diesel oil and lubricating oil

Answer: D

186. What kind of bonding do common gases that exist in free state as diatomic molecules
experiences?
A. Ionic bonds C. Covalent bonds
B. Metallic bonds D. Nuclear bonds

Answer: C

187. When two or more light atoms have sufficient energy (available only at high temperatures
and velocities) to fuse together to form a heavier nucleus the process is called
___________.
A. fusion C. fission
B. the photoelectric effect D. the Compton effect

Answer: A

188. What is formed during incomplete combustion of carbon in fuels?

A. Carbon dioxide C. Carbon monoxide
B. Nitrogen oxide D. Oxygenated fuel

Answer: C

189. A gas produced by the combustion of fuel oil and cannot be found in the flue gases is
___________.
A. oxygen C. nitrogen
B. hydrogen D. carbon dioxide

Answer: B

190. Which of the following chemical reactions in which heat is absorbed?

A. Heat reaction C. Endothermic reaction
B. Exothermic reaction D. Combustion reaction

Answer: C

191. It is a chemical reaction in which heat is given off.

A. Heat reaction C. Endothermic reaction
B. Exothermic reaction D. Combustion reaction

Answer: B

192. A colorless, odorless mixture of nitrogen and oxygen, with traces of other gases water vapor
and same impurities.
A. Air C. Helium
B. Water gas D. Nitrite

Answer: A

193. The transfer of air and air characteristics by horizontal motion is called ___________.
A. convection C. air transfer
B. advection D. adhesion

Answer: B
194. The process of separating two or more liquids by means of the difference in their boiling
point.
A. Engler distillation
B. Fractional distillation
C. Gas scrubbing
D. Fractional crystallization

Answer: B

195. The gaseous products of combustion of a boiler which contains carbon dioxide, carbon
monoxide, oxygen. nitrogen and water vapor is called
A. Flue gas C. Producer gas
B. Product gas D. Universal gas

Answer: A

196. A substance whose burning with oxygen yields heat energy such as coal, petroleum and
natural gas.
A. Air C. Fluid
B. Fuel D. Gas

Answer: B

197. Stoichiometric ratio is ___________.

A. chemically correct air-fuel ratio by volume
B. chemically correct air-fuel ratio by weight
C. theoretical mixture of air for complete combustion
D. actual ratio of air to fuel for maximum efficiency

Answer: B

198. In an oxidation - reduction chemical reaction, all of the following occur except
____________.
A. the exchange of electrons between elements
B. elements becoming more positive
C. elements becoming more negative
D. nuclear fusion
Answer: D

199. The residual oil left after the distillation of gasoline and kerosene from crude petroleum;
yellow to brown oil, used as a diesel fuel and for enriching water gas.
A. Diesel oil C. Gasoline oil
B. LPG D. Gas oil

Answer: D

200. A fuel gas obtained by the destructive distillation of soft coal is called ____________.
A. Gas scrub C. Coal gas
B. Alcogas D. Water gas

Answer: C

201. Removing of impurities from a gas by bubbling it through a liquid purifying agent is called
_________.
A. Gas scrubbing C. Gas purifying
B. Gas liquefying D. Gas bubbling

Answer: A

202. A finely divided carbon deposit by the smoke or flame is called ____________.
A. Fly ash C. Soot
B. Residue D. All of these

Answer: C

203. Kinematics and dynamic viscosity vary from each other only by a factor equal to the
__________.
A. fluid density C. temperature
B. pressure D. specific gas constant

Answer: A

204. The following properties are different for isomers of the same chemical compound except
_______.
A. density
B. melting point
C. number of atoms in a mole of each isomers
D. specific heat

Answer: C

205. The tendency of a pure compound to be composed of the same elements combined in a
definite proportion by mass.
A. Avogadro's law
B. Boyle's law
C. The law of definite proportions
D. Le Chatelier's principle

Answer: C