OBT3- Chapter 14 Questions and
Already Passed Answers 2026-2027
Updated.
Which of the following statements is correct?
Pressure is defined as:
a) Weight per cubic foot.
b) Force (as measured by weight) exerted against known area.
c) Force (as measured by weight) exerted against known volume.
d) All of the listed choices - Answer B
Which of the following statements is correct?
a) Gases flow from a low pressure to a higher pressure.
b) Gases do not flow unless pushed by mechanical devices.
c) Gases flow from a high pressure to a lower pressure.
d) Gases flow only under high pressure. - Answer C
Which of the following statements is correct:
a) Draft pressure measurements employ the inches of water column scale
b) Approximately 28 of water column pressure equals 1 lb. per square i of gauge pressure (psig).
c) Pascals are small units of pressure in the metric measurement system
d) of the listed choices. - Answer D
Atmospheric pressure____________( increases decreases ) with increased height above sea
level and __________ (varies or stays the same) with changing weather systems and conditions.
- Answer Decreases, varies
Which of the following statements is correct?
a) Zero absolute pressure is the same as zero atmospheric pressure.
b) Positive gauge pressure is the same as negative
atmospheric pressure.
c) Vacuum pressure is less than atmospheric pressure.
d) Positive pressure is less than atmospheric pressure. - Answer C
, True or False:
A tightly sealed house with few cracks or openings will assist in air delivery to the burner and
venting of the products of combustion? - Answer False
Define draft intensity - Answer A current of air
True or False:
To adjust any draft measurement gauge to read zero, one of the two sensing ports on the
instrument must be plugged - Answer False
The greater the pressure difference from zero atmospheric pressure the _________________
(greater or lesser) the draft intensity and the ______________ (greater or lesser) the flow rate
from _______________ (high to low or low to high) pressure. - Answer Greater, greater, high
to low
10. Which of the following statements is correct:
a) An incline manometer is a hand-held measuring instrument.
b) A Draftrite gauge can be held at any angle while taking the draft measurement.
c) A MZF Draft gauge is a larger version of the Draftrite and can also be hand-held while taking
the draft measurement.
d) Electronic pressure meters do not have to be level or free of vibration while taking the draft
measurement - Answer D
True or False:
An incline manometer is ideal for checking the calibration or accuracy of other draft measuring
instruments because it directly indicates pressure - Answer True
Explain why a negative pressure inside the appliance and vent connector does not cause air to
flow down the chimney to equalize the lower pressure - Answer The negative measurement
is actually a suction pressure created by the higher pressure hot flue gases in the vent that are
flowing toward the lower atmospheric pressure.
Which of the following statements is correct:
a) Air supply made available to a burner is always at atmospheric pressure and never higher
b) Draft tests are best conducted when the appliance is not operating
c) Draft tests are best operation conducted when the appliance is at steady-state operation.
d) Draft tests are best conducted when the appliance is just activated. - Answer C
Already Passed Answers 2026-2027
Updated.
Which of the following statements is correct?
Pressure is defined as:
a) Weight per cubic foot.
b) Force (as measured by weight) exerted against known area.
c) Force (as measured by weight) exerted against known volume.
d) All of the listed choices - Answer B
Which of the following statements is correct?
a) Gases flow from a low pressure to a higher pressure.
b) Gases do not flow unless pushed by mechanical devices.
c) Gases flow from a high pressure to a lower pressure.
d) Gases flow only under high pressure. - Answer C
Which of the following statements is correct:
a) Draft pressure measurements employ the inches of water column scale
b) Approximately 28 of water column pressure equals 1 lb. per square i of gauge pressure (psig).
c) Pascals are small units of pressure in the metric measurement system
d) of the listed choices. - Answer D
Atmospheric pressure____________( increases decreases ) with increased height above sea
level and __________ (varies or stays the same) with changing weather systems and conditions.
- Answer Decreases, varies
Which of the following statements is correct?
a) Zero absolute pressure is the same as zero atmospheric pressure.
b) Positive gauge pressure is the same as negative
atmospheric pressure.
c) Vacuum pressure is less than atmospheric pressure.
d) Positive pressure is less than atmospheric pressure. - Answer C
, True or False:
A tightly sealed house with few cracks or openings will assist in air delivery to the burner and
venting of the products of combustion? - Answer False
Define draft intensity - Answer A current of air
True or False:
To adjust any draft measurement gauge to read zero, one of the two sensing ports on the
instrument must be plugged - Answer False
The greater the pressure difference from zero atmospheric pressure the _________________
(greater or lesser) the draft intensity and the ______________ (greater or lesser) the flow rate
from _______________ (high to low or low to high) pressure. - Answer Greater, greater, high
to low
10. Which of the following statements is correct:
a) An incline manometer is a hand-held measuring instrument.
b) A Draftrite gauge can be held at any angle while taking the draft measurement.
c) A MZF Draft gauge is a larger version of the Draftrite and can also be hand-held while taking
the draft measurement.
d) Electronic pressure meters do not have to be level or free of vibration while taking the draft
measurement - Answer D
True or False:
An incline manometer is ideal for checking the calibration or accuracy of other draft measuring
instruments because it directly indicates pressure - Answer True
Explain why a negative pressure inside the appliance and vent connector does not cause air to
flow down the chimney to equalize the lower pressure - Answer The negative measurement
is actually a suction pressure created by the higher pressure hot flue gases in the vent that are
flowing toward the lower atmospheric pressure.
Which of the following statements is correct:
a) Air supply made available to a burner is always at atmospheric pressure and never higher
b) Draft tests are best conducted when the appliance is not operating
c) Draft tests are best operation conducted when the appliance is at steady-state operation.
d) Draft tests are best conducted when the appliance is just activated. - Answer C
