COMMERCIAL BOILERS FINAL EXAM
2025 QUESTIONS AND ANSWERS
Which unit of measurement is used to measure mechanical potential energy? - ANS Foot-
pounds
Heat which brings about a change in the physical state of a substance without a change in
temperature, is called ______. - ANS latent heat
Which of the listed methods of heat transfer takes place when two substances of different
temperatures are in physical contact with each other? - ANS conduction
Which line on the graph shown in the illustration indicates latent heat of fusion? See illustration
SG-0001. - ANS Line 2
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, The sum of the sensible heat and the latent heat of any substance is known as _____. -
ANS total heat
Which of the following modes of heat transfer does NOT require any physical contact between
a warmer and a cooler substance? - ANS Radiation
When vapor is in contact with and remains at the same temperature as the boiling liquid from
which it was generated, the vapor and liquid are said to be in a/an ___. - ANS saturated
condition
Steam tables can be used to obtain the _____. - ANS values for properties of water and
steam vapor at various conditions
The heat required to change a substance from a solid to a liquid while at its freezing
temperature, is known as the latent heat of ____. - ANS fusion
Which of the following terms could be applied to the simple definition the energy of motion'? -
2
ANS Kinetic Energy
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, When the boiling temperature of a steam boiler is increased, which of the following effects will
occur with relation to the pressure and the specific volume of the steam? - ANS The steam
pressure will increase and the specific volume will decrease.
Which of the following forms of energy is released through the process of fuel combustion? -
ANS Chemical energy
The heat identified by only a change in temperature is known as ____. - ANS sensible heat
Which of the listed values represents the temperature of saturated vapor for water at a
pressure of 14.7 psia? - ANS 212°F (100°C)
Which of the following terms is used to indicate that additional BTU's will result in a
temperature change? - ANS Sensible heat
The energy associated with atoms forming molecules is known as____. - ANS Chemical
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Energy
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, As steam accomplishes work in an engine or turbine, the pressure of the steam is reduced
because it _____. - ANS expands in volume
The heat required to change a substance from a liquid to a gas without experiencing a
temperature change, is defined as the latent heat of ____. - ANS vaporization
Which of the following terms would best describe the temperature at which a liquid boils at a
given pressure? - ANS Saturation temperature
In which of the listed components is chemical energy converted to thermal energy with regards
to boiler operation? - ANS Furnace
A Boiler Horsepower is defined as ____. - ANS Evaporation of 34.5 lb. of water from and at
212 degrees per 8 hours2
A boiler's steam pressure gauge reads 150. What is the absolute pressure? - ANS 164.7
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2025 QUESTIONS AND ANSWERS
Which unit of measurement is used to measure mechanical potential energy? - ANS Foot-
pounds
Heat which brings about a change in the physical state of a substance without a change in
temperature, is called ______. - ANS latent heat
Which of the listed methods of heat transfer takes place when two substances of different
temperatures are in physical contact with each other? - ANS conduction
Which line on the graph shown in the illustration indicates latent heat of fusion? See illustration
SG-0001. - ANS Line 2
1
Page
@COPYRIGHT SIRJOEL 2025/2026
, The sum of the sensible heat and the latent heat of any substance is known as _____. -
ANS total heat
Which of the following modes of heat transfer does NOT require any physical contact between
a warmer and a cooler substance? - ANS Radiation
When vapor is in contact with and remains at the same temperature as the boiling liquid from
which it was generated, the vapor and liquid are said to be in a/an ___. - ANS saturated
condition
Steam tables can be used to obtain the _____. - ANS values for properties of water and
steam vapor at various conditions
The heat required to change a substance from a solid to a liquid while at its freezing
temperature, is known as the latent heat of ____. - ANS fusion
Which of the following terms could be applied to the simple definition the energy of motion'? -
2
ANS Kinetic Energy
Page
@COPYRIGHT SIRJOEL 2025/2026
, When the boiling temperature of a steam boiler is increased, which of the following effects will
occur with relation to the pressure and the specific volume of the steam? - ANS The steam
pressure will increase and the specific volume will decrease.
Which of the following forms of energy is released through the process of fuel combustion? -
ANS Chemical energy
The heat identified by only a change in temperature is known as ____. - ANS sensible heat
Which of the listed values represents the temperature of saturated vapor for water at a
pressure of 14.7 psia? - ANS 212°F (100°C)
Which of the following terms is used to indicate that additional BTU's will result in a
temperature change? - ANS Sensible heat
The energy associated with atoms forming molecules is known as____. - ANS Chemical
3
Page
Energy
@COPYRIGHT SIRJOEL 2025/2026
, As steam accomplishes work in an engine or turbine, the pressure of the steam is reduced
because it _____. - ANS expands in volume
The heat required to change a substance from a liquid to a gas without experiencing a
temperature change, is defined as the latent heat of ____. - ANS vaporization
Which of the following terms would best describe the temperature at which a liquid boils at a
given pressure? - ANS Saturation temperature
In which of the listed components is chemical energy converted to thermal energy with regards
to boiler operation? - ANS Furnace
A Boiler Horsepower is defined as ____. - ANS Evaporation of 34.5 lb. of water from and at
212 degrees per 8 hours2
A boiler's steam pressure gauge reads 150. What is the absolute pressure? - ANS 164.7
4
Page
@COPYRIGHT SIRJOEL 2025/2026
