G2 Exam Prep Latest Update 2025-2026 300
Questions and 100% Verified Correct Answers
Guaranteed A+
________________ is the principle of thermal expansion of solid.
a.
Metal contract when heated and expand when cooled
b.
Metal melt while heated and contract when cooled
c.
Metal expands when heated and contract when cooled
d.
All of the above. - CORRECT ANSWER: Metal expands when heated and contract
when cooled
15 psi is equivalent to?
a.
15 feet of head
b.
34.5 feet of head
c.
,420 feet of head
d.
1.87 feet of head - CORRECT ANSWER: 34.5 feet of head (PSI*2.31)
3/8 NPS black iron pipe shall?
a. Not be used for propane
b. Not be used in a concealed location
c. Not be used for natural gas
d. Not be used for indoors - CORRECT ANSWER: Not be used in a concealed location
(6.3.9)
A _______________ is a device that changes its electrical resistance with a change in
temperature.
a.
Diode
b.
Thermopile
c.
Thermocouple
d.
Thermistor - CORRECT ANSWER: Thermistor
,A "0" reading across a closed switch indicates?
a. The switch is shorted out
b. The switch is faulty
c. The switch is good
d. The switch burned out - CORRECT ANSWER: The switch is faulty
A 90,000 BTU Category IV furnace shall have a minimum vent termination distance
from a Window or door of?
a.
2400mm (96 in)
b.
900mm (36 in)
c.
300mm (12 in)
d.
1800m111(72 in) - CORRECT ANSWER: 300mm (12 in) (8.14.8)
A certified power venter that is used as an add-on to a water heater can only be used if
the input does not exceed:
a.
60,000 Btuh
, b.
75,000 Btuh
c.
70,000 Btuh
d.
50,000 Btuh - CORRECT ANSWER: 50,000 Btuh (8.29.2)
A combination fan limit control on a residential warm air furnace shuts the fan off after
completing the heating cycle at?
a. 75 °F
b. 250°F
c. 90°F
d. 140°F - CORRECT ANSWER: 90°F
A converted boiler shall be installed with _______________ minimum clearances from
the sides and rear to a combustible material?
a.
48 in (1200 mm)
b.
18 in (450 mm)
c.
1 in (25 mm)
Questions and 100% Verified Correct Answers
Guaranteed A+
________________ is the principle of thermal expansion of solid.
a.
Metal contract when heated and expand when cooled
b.
Metal melt while heated and contract when cooled
c.
Metal expands when heated and contract when cooled
d.
All of the above. - CORRECT ANSWER: Metal expands when heated and contract
when cooled
15 psi is equivalent to?
a.
15 feet of head
b.
34.5 feet of head
c.
,420 feet of head
d.
1.87 feet of head - CORRECT ANSWER: 34.5 feet of head (PSI*2.31)
3/8 NPS black iron pipe shall?
a. Not be used for propane
b. Not be used in a concealed location
c. Not be used for natural gas
d. Not be used for indoors - CORRECT ANSWER: Not be used in a concealed location
(6.3.9)
A _______________ is a device that changes its electrical resistance with a change in
temperature.
a.
Diode
b.
Thermopile
c.
Thermocouple
d.
Thermistor - CORRECT ANSWER: Thermistor
,A "0" reading across a closed switch indicates?
a. The switch is shorted out
b. The switch is faulty
c. The switch is good
d. The switch burned out - CORRECT ANSWER: The switch is faulty
A 90,000 BTU Category IV furnace shall have a minimum vent termination distance
from a Window or door of?
a.
2400mm (96 in)
b.
900mm (36 in)
c.
300mm (12 in)
d.
1800m111(72 in) - CORRECT ANSWER: 300mm (12 in) (8.14.8)
A certified power venter that is used as an add-on to a water heater can only be used if
the input does not exceed:
a.
60,000 Btuh
, b.
75,000 Btuh
c.
70,000 Btuh
d.
50,000 Btuh - CORRECT ANSWER: 50,000 Btuh (8.29.2)
A combination fan limit control on a residential warm air furnace shuts the fan off after
completing the heating cycle at?
a. 75 °F
b. 250°F
c. 90°F
d. 140°F - CORRECT ANSWER: 90°F
A converted boiler shall be installed with _______________ minimum clearances from
the sides and rear to a combustible material?
a.
48 in (1200 mm)
b.
18 in (450 mm)
c.
1 in (25 mm)
