COMMERCIAL WIRING EXAM QUESTIONS AND 100%
CORRECT ANSWERS|2025/2026|GUARANTEED A+
The proper size and type of conductor must be installed to comply with manufacturers
installation instructions - ANSWER- True
The maximum current, in amperes, that a conductor can carry continuously under the
conditions of abuse without exceeding its temperature rating. - ANSWER- Ampacity
Allowable ampacities of 310.16 (B) (16) is based on not more than ____ current-carrying
conductors in a raceway, cable, or earth based on an ambient temperature of _____ degrees
F. - ANSWER- 3, 86
Conductors with a ___ insulation designation have a higher ampacity in a wet location than
do conductors without the designation. - ANSWER- -2
Conductors with -2 designation system are rated at ____ in wet and dry locations. -
ANSWER- 90 degrees F
Which of the following two insulation types are more likely to soften when heated? THWN
or XHHN. - ANSWER- THWN
If nine current-carrying conductors are installed in one raceway for a length greater than
24inches, the allowable ampacity must be reduce to ____ . - ANSWER- 70%
If conduits or cables are installed on or withing 7/8 in. of a rooftop with sunlight exposure,
the following temperature must be added to the ambient temperature for the application of
the correction factor: ____ F. - ANSWER- 60 degrees
Spare conductors installed in a raceway are required to be counted for _____ and ____
purposes. - ANSWER- Conductor fill, derating
, The neutral conductor of a 2-wire circuit from a 3-phase, 4-wire system is required to be
counted as as a current-carrying conductor in a raceway or cable. - ANSWER- True
If a conductor is installed so not more than 50% is in a cooler area and 50% is in a hotter
ambient temperature, the ampacity determined in the cooler are can be used for the entire
run. - ANSWER- False
The neutral conductor of a 3-wire circuit from a 3-phase, 4-wire system is required to be
counted as a current-carrying conductor in a raceway or cable. - ANSWER- True
The neutral conductor of a 3-wire circuit from a 1-phase, 3-wire system is required to be
counted as a current-carrying conductor in a raceway or cable. - ANSWER- False
A ___ load is any load that is on for 3 hours or more. - ANSWER- Continuous
Overcurrent protection for continuous loads must be sized at no less than ____ of the load. -
ANSWER- 125%
Compensation for voltage drop ___ generally required by the NEC. - ANSWER- Is not
Heat generated in a conductor over a short period of time is ____., expressed in ampere-
square seconds. - ANSWER- H=IxI(t)
Heat generated in a conductor over a long period of time is ____, expressed in watts. -
ANSWER- W=IxI(R)
____ is 90 degrees C in dry, 75 in wet. - ANSWER- Type XHHW
The minimum size conductor to be run in parallel is ____. - ANSWER- 1/0 AWG
CORRECT ANSWERS|2025/2026|GUARANTEED A+
The proper size and type of conductor must be installed to comply with manufacturers
installation instructions - ANSWER- True
The maximum current, in amperes, that a conductor can carry continuously under the
conditions of abuse without exceeding its temperature rating. - ANSWER- Ampacity
Allowable ampacities of 310.16 (B) (16) is based on not more than ____ current-carrying
conductors in a raceway, cable, or earth based on an ambient temperature of _____ degrees
F. - ANSWER- 3, 86
Conductors with a ___ insulation designation have a higher ampacity in a wet location than
do conductors without the designation. - ANSWER- -2
Conductors with -2 designation system are rated at ____ in wet and dry locations. -
ANSWER- 90 degrees F
Which of the following two insulation types are more likely to soften when heated? THWN
or XHHN. - ANSWER- THWN
If nine current-carrying conductors are installed in one raceway for a length greater than
24inches, the allowable ampacity must be reduce to ____ . - ANSWER- 70%
If conduits or cables are installed on or withing 7/8 in. of a rooftop with sunlight exposure,
the following temperature must be added to the ambient temperature for the application of
the correction factor: ____ F. - ANSWER- 60 degrees
Spare conductors installed in a raceway are required to be counted for _____ and ____
purposes. - ANSWER- Conductor fill, derating
, The neutral conductor of a 2-wire circuit from a 3-phase, 4-wire system is required to be
counted as as a current-carrying conductor in a raceway or cable. - ANSWER- True
If a conductor is installed so not more than 50% is in a cooler area and 50% is in a hotter
ambient temperature, the ampacity determined in the cooler are can be used for the entire
run. - ANSWER- False
The neutral conductor of a 3-wire circuit from a 3-phase, 4-wire system is required to be
counted as a current-carrying conductor in a raceway or cable. - ANSWER- True
The neutral conductor of a 3-wire circuit from a 1-phase, 3-wire system is required to be
counted as a current-carrying conductor in a raceway or cable. - ANSWER- False
A ___ load is any load that is on for 3 hours or more. - ANSWER- Continuous
Overcurrent protection for continuous loads must be sized at no less than ____ of the load. -
ANSWER- 125%
Compensation for voltage drop ___ generally required by the NEC. - ANSWER- Is not
Heat generated in a conductor over a short period of time is ____., expressed in ampere-
square seconds. - ANSWER- H=IxI(t)
Heat generated in a conductor over a long period of time is ____, expressed in watts. -
ANSWER- W=IxI(R)
____ is 90 degrees C in dry, 75 in wet. - ANSWER- Type XHHW
The minimum size conductor to be run in parallel is ____. - ANSWER- 1/0 AWG
