G2 EXAM PREP 140 QUESTIONS & CORRECT
ANSWERS LATEST 2025
What is the equivalent length of a NPS 2" Schedule 40, 90* threaded elbow -
ANSWER-5.17 Feet
What diameter and length of a dirt pocket is required when a drop line is 3" in
diameter - ANSWER-2" diameter/3" long
When sizing a branch line, what is the minimum size of job fabricated welded
fitting that can be used on a NPS 6" gas supply header - ANSWER-2" NPS
The instrument used to determine the polarity of an appliance power supply is
the - ANSWER-Voltmeter
Direct current travels - ANSWER-In one direction
A 120V power supply for a residential electrical circuit is taken from the -
ANSWER-Load side of one branch circuit breaker and neutral lug
A hard sharp pilot flame indicates - ANSWER-The orifice is too small
Which tool is used to determine if the windings on an electric motor have shorted
- ANSWER-Voltmeter
,When the voltage has been determined to be approximately 120V, which scale on
an analog meter should be selected for the most accuracy - ANSWER-0-125V
One millivolt is equal to - ANSWER-1/1000 volt
When checking a circuit of an unknown voltage using an analog meter with 0-30V,
0-125V, 0-250V and 0-600V which scale should be selected - ANSWER-0-600 V
The 24 V control circuit supply for a residential gas furnace comes from a -
ANSWER-120/24 step down transformer
As gauge number of a conductor increases, it's current carrying capacity -
ANSWER-Decreases
The instrument used to determine potential difference in an electrical circuit is
the - ANSWER-Voltmeter
The open circuit test reading of a thermocouple should be in the range of -
ANSWER-25-30 mV
As the diameter of a wire increase, it's resistance - ANSWER-decreases
Millivolt wiring should be isolated from line voltage wiring because - ANSWER-The
line voltage will induce a voltage into the millivolt wiring
, A schematic diagram is used to - ANSWER-Indicate how the system works
A thermopile or power pile generates - ANSWER-Hundreds of Millivolts (up to 750
mV)
An operating aqua stat is what type of control - ANSWER-Normally closed
The resistance of a heating thermistor does what as its temperature rises -
ANSWER-Decreases
An intermittent pilot is present - ANSWER-From the time there is a call for heat
until the call has ended
A probe type low water cut-off switch is what type of control - ANSWER-Normally
open
How much of the appliance-rated gas is supplied to a burner using a two stage gas
valve the thermostat calls for the second stage of heat - ANSWER-100%
A diode - ANSWER-Allows current flow in one direction only
A thermostat serving a unit which has seperate heating and cooling control
transformer and has one stage of heating and one stage of cooling is a - ANSWER-
Single pole double throw
What safety control protects a steam boiler if the condensate pump fails to return
condensate to the boiler - ANSWER-Low water cut off
ANSWERS LATEST 2025
What is the equivalent length of a NPS 2" Schedule 40, 90* threaded elbow -
ANSWER-5.17 Feet
What diameter and length of a dirt pocket is required when a drop line is 3" in
diameter - ANSWER-2" diameter/3" long
When sizing a branch line, what is the minimum size of job fabricated welded
fitting that can be used on a NPS 6" gas supply header - ANSWER-2" NPS
The instrument used to determine the polarity of an appliance power supply is
the - ANSWER-Voltmeter
Direct current travels - ANSWER-In one direction
A 120V power supply for a residential electrical circuit is taken from the -
ANSWER-Load side of one branch circuit breaker and neutral lug
A hard sharp pilot flame indicates - ANSWER-The orifice is too small
Which tool is used to determine if the windings on an electric motor have shorted
- ANSWER-Voltmeter
,When the voltage has been determined to be approximately 120V, which scale on
an analog meter should be selected for the most accuracy - ANSWER-0-125V
One millivolt is equal to - ANSWER-1/1000 volt
When checking a circuit of an unknown voltage using an analog meter with 0-30V,
0-125V, 0-250V and 0-600V which scale should be selected - ANSWER-0-600 V
The 24 V control circuit supply for a residential gas furnace comes from a -
ANSWER-120/24 step down transformer
As gauge number of a conductor increases, it's current carrying capacity -
ANSWER-Decreases
The instrument used to determine potential difference in an electrical circuit is
the - ANSWER-Voltmeter
The open circuit test reading of a thermocouple should be in the range of -
ANSWER-25-30 mV
As the diameter of a wire increase, it's resistance - ANSWER-decreases
Millivolt wiring should be isolated from line voltage wiring because - ANSWER-The
line voltage will induce a voltage into the millivolt wiring
, A schematic diagram is used to - ANSWER-Indicate how the system works
A thermopile or power pile generates - ANSWER-Hundreds of Millivolts (up to 750
mV)
An operating aqua stat is what type of control - ANSWER-Normally closed
The resistance of a heating thermistor does what as its temperature rises -
ANSWER-Decreases
An intermittent pilot is present - ANSWER-From the time there is a call for heat
until the call has ended
A probe type low water cut-off switch is what type of control - ANSWER-Normally
open
How much of the appliance-rated gas is supplied to a burner using a two stage gas
valve the thermostat calls for the second stage of heat - ANSWER-100%
A diode - ANSWER-Allows current flow in one direction only
A thermostat serving a unit which has seperate heating and cooling control
transformer and has one stage of heating and one stage of cooling is a - ANSWER-
Single pole double throw
What safety control protects a steam boiler if the condensate pump fails to return
condensate to the boiler - ANSWER-Low water cut off
