2026 QUESTIONS WITH PRACTICE SOLUTION
GRADED A+
◉ 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