NEC CODE EXAM QUESTIONS
AND ANSWERS
A 1/0 THWN in a wet location has a rated ampacity of 150 amperes.
If the same conductor is used at a temperature of 400 degrees
Celsius. What is the corrected ampacity? -
correct answer ✅Temperature correction factor of 1/0 THWN
Conductor for 40-750 C = 0.88 The corrected ampacity = 0.88 * 150
= 132 amperes
The capacity of the conductor is 150 amperes. If five conductors are
placed in a flexible cord, what is the maximum conductor ampacity
allowed for each conductor? -
correct answer ✅For 5 conductors in flexible cord allowed
ampacity percentage = 80 % of rated amapcity Allowed amapcity of
each conductor with 150 Ampere rating = 150 * 0.8 = 120 amperes.
If the raceway contains four 1/0 THWN conductors, what is the
ampacity of a 1/0 THWN conductor in a dry location at a
temperature of 1040 F? -
correct answer ✅The conductor ampacity of 1/0 THWN in dry
location ( 900C) = 170 amperes ( NEC Table 310.15(B)(16)) Ambient
temperature correction factor at 1080F = 0.91 ( NEC Table
310.15(B)(2)) Raceway conductor bundle adjustment factor for 4
conductors = 0.8 ( NEC Table 310.15(B)(3)(a)) corrected ampacity =
170 * 0.8*0.91 = 124 amperes
,NEC CODE EXAM QUESTIONS
AND ANSWERS
The connected load of a single family dwelling unit is 4000 VA. The
calculated demand load is which of the following? -
correct answer ✅First 3000 VA the demand factor is 100% = 3000
* 100 % = 3000 VA remaining (4000-3000) = 1000 ( demand factor =
35%) = 1000 * 0.35 = 350 VA total demand load = 3000 + 350 =
3350 VA
Which of the following is allowed to be supplied by circuits not
exceeding 120 volts, nominal, between conductors? -
correct answer ✅Auxiliary equipment of electric-discharge lamps.
Cord-and-plug-connected or permanently connected utilization
equipment
The terminals of lampholders applied within their voltage ratings
X-All of the above
Where a cable or raceway type wiring method is installed through
bored holes in joist, rafters, or wood members, in both concealed
and exposed locations, holes must be bored so that the edge of the
hole is __________ in. or more from the nearest edge of the wood
member. Where the distance is not possible, the cable or raceway
must be protected from penetration by nails or screws by use of a
steel bushing or plate, __________ in thick or more, and of the
,NEC CODE EXAM QUESTIONS
AND ANSWERS
correct length and width installed to cove -
correct answer ✅1.25" | 0.0625"
A device intended for the protection of personnel that functions to
de-energize a circuit or portion thereof within an established period
of time when a ground-fault current exceeds the values established
for a Class A device. -
correct answer ✅Ground-Fault Circuit Interrupter (GFCI)
All switches and circuit breakers used as switches shall be located
so the operating handle, when in its highest position, is not more
than __________ above the floor or working platform. -
correct answer ✅6 ft. 7 in.
For conductors on a branch circuit that supplies luminaires in a
residence, what is the maximum allowable voltage between
conductors on a branch circuit supplying luminaires in a residence?
-
correct answer ✅120 volts
All conductors of the same circuit and, where used, the grounded
conductor and all equipment grounding conductors and bonding
, NEC CODE EXAM QUESTIONS
AND ANSWERS
conductors shall be contained within the same __________. -
correct answer ✅raceway
An organization, office, or individual responsible for enforcing the
requirements of a code or standard, or for approving equipment,
materials, an installation, or a procedure. -
correct answer ✅AHJ
Snap switches must not be ganged or grouped in enclosures with
other receptacles, snap switches, or similar devices, unless they are
placed so that voltage is __________ volts or less between adjacent
devices, or unless placed in enclosures with securely installed,
identified barriers between adjacent devices. -
correct answer ✅300 volts
If a single receptacle is installed on an individual branch circuit, it
must have an ampere rating of not less than __________of the
branch circuit. -
correct answer ✅100%
What is the minimum burial depth in inches, in a trench below 2
inch thick concrete or equivalent for residential branch circuits
rated at up to 120 volts with GFCI protection and overcurrent
AND ANSWERS
A 1/0 THWN in a wet location has a rated ampacity of 150 amperes.
If the same conductor is used at a temperature of 400 degrees
Celsius. What is the corrected ampacity? -
correct answer ✅Temperature correction factor of 1/0 THWN
Conductor for 40-750 C = 0.88 The corrected ampacity = 0.88 * 150
= 132 amperes
The capacity of the conductor is 150 amperes. If five conductors are
placed in a flexible cord, what is the maximum conductor ampacity
allowed for each conductor? -
correct answer ✅For 5 conductors in flexible cord allowed
ampacity percentage = 80 % of rated amapcity Allowed amapcity of
each conductor with 150 Ampere rating = 150 * 0.8 = 120 amperes.
If the raceway contains four 1/0 THWN conductors, what is the
ampacity of a 1/0 THWN conductor in a dry location at a
temperature of 1040 F? -
correct answer ✅The conductor ampacity of 1/0 THWN in dry
location ( 900C) = 170 amperes ( NEC Table 310.15(B)(16)) Ambient
temperature correction factor at 1080F = 0.91 ( NEC Table
310.15(B)(2)) Raceway conductor bundle adjustment factor for 4
conductors = 0.8 ( NEC Table 310.15(B)(3)(a)) corrected ampacity =
170 * 0.8*0.91 = 124 amperes
,NEC CODE EXAM QUESTIONS
AND ANSWERS
The connected load of a single family dwelling unit is 4000 VA. The
calculated demand load is which of the following? -
correct answer ✅First 3000 VA the demand factor is 100% = 3000
* 100 % = 3000 VA remaining (4000-3000) = 1000 ( demand factor =
35%) = 1000 * 0.35 = 350 VA total demand load = 3000 + 350 =
3350 VA
Which of the following is allowed to be supplied by circuits not
exceeding 120 volts, nominal, between conductors? -
correct answer ✅Auxiliary equipment of electric-discharge lamps.
Cord-and-plug-connected or permanently connected utilization
equipment
The terminals of lampholders applied within their voltage ratings
X-All of the above
Where a cable or raceway type wiring method is installed through
bored holes in joist, rafters, or wood members, in both concealed
and exposed locations, holes must be bored so that the edge of the
hole is __________ in. or more from the nearest edge of the wood
member. Where the distance is not possible, the cable or raceway
must be protected from penetration by nails or screws by use of a
steel bushing or plate, __________ in thick or more, and of the
,NEC CODE EXAM QUESTIONS
AND ANSWERS
correct length and width installed to cove -
correct answer ✅1.25" | 0.0625"
A device intended for the protection of personnel that functions to
de-energize a circuit or portion thereof within an established period
of time when a ground-fault current exceeds the values established
for a Class A device. -
correct answer ✅Ground-Fault Circuit Interrupter (GFCI)
All switches and circuit breakers used as switches shall be located
so the operating handle, when in its highest position, is not more
than __________ above the floor or working platform. -
correct answer ✅6 ft. 7 in.
For conductors on a branch circuit that supplies luminaires in a
residence, what is the maximum allowable voltage between
conductors on a branch circuit supplying luminaires in a residence?
-
correct answer ✅120 volts
All conductors of the same circuit and, where used, the grounded
conductor and all equipment grounding conductors and bonding
, NEC CODE EXAM QUESTIONS
AND ANSWERS
conductors shall be contained within the same __________. -
correct answer ✅raceway
An organization, office, or individual responsible for enforcing the
requirements of a code or standard, or for approving equipment,
materials, an installation, or a procedure. -
correct answer ✅AHJ
Snap switches must not be ganged or grouped in enclosures with
other receptacles, snap switches, or similar devices, unless they are
placed so that voltage is __________ volts or less between adjacent
devices, or unless placed in enclosures with securely installed,
identified barriers between adjacent devices. -
correct answer ✅300 volts
If a single receptacle is installed on an individual branch circuit, it
must have an ampere rating of not less than __________of the
branch circuit. -
correct answer ✅100%
What is the minimum burial depth in inches, in a trench below 2
inch thick concrete or equivalent for residential branch circuits
rated at up to 120 volts with GFCI protection and overcurrent
