National Electrical Code (NEC) | Complete Code Exam Review & Practice Questions | 2026-2027
Given: Nine (9) size 6 awg type XHHW conductors are in a 37 amps
conduit 50 feet long in a wet location and operate at 110
degrees F. for calculation purposes consider termination as
rated for 75 degrees C. What is the maximum ampacity of
each conductor?
Given : In a normal operation , the load on an overcurrent Answer 80 %
device located in a panelboard will continue for 4 hours .
Disregarding exceptions , the maximum total load allowed
for this circuit is what percent of the circuit overcurrent
device rating ?
Given: a grounding ring consists of 300 feet if bare copper 2 awg
wire encircling a building in direct contact with the earth
and buried 3 feet deep. What minimum size copper wire is
allowed for this grounding ring
Given: only the following type THW conductors are 6 inch x 6 inch
installed in an auxiliary gutter. 8,size 1 awg conductors; 7,
size 2 awg conductors; 4, size 3 awg conductors; 6, size 6
awg conductors. What minimum size auxiliary gutter is
required for these 25 conductors
Refer to the illustration. Each of the supply side emt 4/0 awg
conduits contain three 500 kmil(mcm) copper TH@ service
Conductors. One conductor in each conduit is connected
in parallel for each of three phases. AS shown a separate
bonding jumper is installed from each conduit to the
grounded bus terminal. What is the minimum allowable
size for each copper bonding jumper
Refer to the illustration. This installation requires at least 10
how many sealing fittings
Given: A ground rod Electrode is driven at least 8 feet in to needs to be supplemented by one additional electrode
earth. it's resistance to earth measured at 50 ohms.
According to the NEC, this ground rod electrode:
According to the NEC , electrical junction boxes shall be can be rendered accessible
installed so that the wiring contained in the boxes:
fourteen (14) current carrying conductors are in an 80 foot 50%
conduit run operating at 28 decgrees C or 82 degrees F.
Each conductor shall be derated to what percentage of its'
original ampacity
Refer to the illustration, and the conductor colors of Figure 1, because a white wire can never be used as a switch leg return from the switch to
1 and 2, these figures represent circuits wired with the switched outlet
nonmetallic sheathed cable. Assume all grounding
conductors are installed correctly . which figure is not wired
according to the NEC and why
A metal raceway system is installed in the washing area of 1/4 inch
a car wash. what minimum distance from the surface must
the raceway be mounted?
, National Electrical Code (NEC) | Complete Code Exam Review & Practice Questions | 2026-2027
As long as it has continuity top the grounding electrode Steel conduit
system, an equipment grounding conductor may be a:
Which of the following locations is allowable for bonding the service disconnecting means
the grounding electrode conductor to the grounded
service?
Given: The largest service entrance conductor for a 8 awg
commercial building electrical system with a 100 amp main
circuit breaker is size 1/0 awg aluminum. What is the
minimum allowable copper grounding electrode conductor
for the system?
A remote gasoline pump is located outdoors. Electrical Class 1 Group D division 2
equipment is installed 12 inches above grade and 9 feet
horizontally from the edge of the pump. This electrical
equipment installation is classified as
if the NEC requires that the electrical disconnect switch be 50
placed within sight of the electrical equipment and controls,
the switch must be within how many feet of the equipment
A feeder is supplying a continuous load of 240 amps, it is 500 kcmil
protected by an overcurrent device rated at 300 amps.
Consider terminations rated at 75 degrees C. What
minimum size type of THW aluminum conductors are
allowed as phase conductors for this feeder?
a 120/240 volt single phase panel has a 92 KVA balanced 750 kcmil
incandescent lighting load. The load is in a stock room
which comes on only 2 hours at a time. What is the
minimum size required of each ungrounded aluminum
THW conductor in the feeder circuit to supply this panel
a metal electrical box contains the following; 3 size 12 awg 18.75 cubic inches
conductors, 3 size 10 awg conductors , 1 flush switch, the
switch is connected to two (2) of the size 12 awg
conductors. There are no other devices or fittings. The
cover plate does not have its capacity marked on it. There
are no grounding conductors. All conductors originate
outside the box. What minimum capacity is required for the
metal electrical box containing these conductors and this
switch?
a 120/240 volt 3 phase, 4 wire, power panel which 296.9 amps
supplies all of the following. 1-15 HP, 240 volt, 3 phase
wound rotor motor; 4-5 HP, 240 volt, 3 phase wound rotor
motors; 6-5HP, 240 volt, single phase motors; 3-1 KW, 240
volt, single phase base board heaters; Each ungrounded
conductor in the subfeeder to this power panel has a total
net calculated load of:
Fluorescent lighting fixture each containing 2 ballasts rated 10
0.8 amps each at 120 volts are to be installed for
continuous general lighting in a store. The over current
protection devices are not listed for continuous operation
at 100 percent of their rating. according the the national
electrical code, what is the maximum number of these
lighting fixtures that may be permanently wired to a 20
amp 120 volt branch circuit
an open fixture in a commercial garage shall be placed 12 feet
over vehicular lanes at a height of at least
, National Electrical Code (NEC) | Complete Code Exam Review & Practice Questions | 2026-2027
a park has 35 mobile home sites. the ungrounded wires in 560 amps
the service to supply this park must be calculated size of at
least:
Where an A/C system operating at less than 1000 volts is Serviced disconnecting means
grounded at any point. This systems grounded conductors
shall run to each:
Given : a building has a 120/208 volt, 3 phase service. A it must be connected to the power grounding electrode system
low voltage system that requires a separate grounding
electrode is installed. Which of the following statements
regarding the low voltage system grounding electrode
conductor is true?
What low voltage classification is assigned to a remote class 1
controlled safety control equipment circuit if failure of the
the equipment to operate induces a direct fire or life
hazard?
open overhead service conductors must have horizontal 3 feet
clearance from a porch of at least how many feet?
Given: A surface mounted florescent lighting fixture that 1-1/2 inches
contains a ballast is to be installed on lay-in ceiling tile that
is made of combustible low density cellulose. The fixture is
not approved for direct contact with the material. How far
must this fixture be spaced from the surface of the
fiberboard?
Given: A store lighting branch circuit operates under a 32 amps
continuous load. The branch circuit rating is 40 amps.
What is the maximum continuous load allowed on this
branch circuit?
Given: An explosion proof metal junction box has a 6
capacity of 27 cubic inches and contains a total of 5 size
12 awg wires. Additional conducts of size 10 awg need to
be added to the box. no grounding conductors, devices nor
fittings are contained in the box. What is the maximum
number of additional size 10 awg conductors that may be
added to this box
Given: a 3 phase, squirrel cage motor with full voltage 175%
reactor starting has no code letter. disregard all
exceptions. the dual element time delay fuse used to
proved short circuit protection for this motor branch circuit
should be sized at what maximum percentage of the motor
full load current?
Given: a dispensing station gasoline pump is located class 1 group d division 2
outdoors. Electrical equipment is installed 12 inches above
grade and 9 feet horizontally from the edge of the pump.
This electrical installation sis classified as?
What type of conductor insulation is required for 13 size 3 THWN
awg conductors that are to be installed in a run of 2 inch
metallic tubing
in a dwelling unit a multiwire branch circuit that supplies one double pole circuit breaker
more than one device on the same yoke may be protected
by
, National Electrical Code (NEC) | Complete Code Exam Review & Practice Questions | 2026-2027
Refer to the illustration, disregarding exceptions, what is 30 inches
the minimum width of a clear working space required by
the NEC as noted by 'A'? (*note : 600 volts or less)
a non locking disconnect for 480 volt motor controller must 50 feet
be visible from the controller and within a maximum of how
far from the controller?
Given: A 30 HP wound rotor induction motor with no code 60 amps
letter is to be connected to a 460 volt 3 phase source.
Disregarding all exceptions, what is the maximum rating
allowed for a non timed delay fuse for short circuit
protection of the motor branch circuit?
A building has the following facilities: 25,000 square feet of 100%
office space, 5,500 square feet for a restaurant; 3,000
square feet for an auditorium. what is the general lighting
load feeder demand factor for this building?
an electrical junction box contains only the following : 3, 22.5 cubic inches
#12 insulated conductors entering the box spliced to 3,
#12 conductor leaving the box. one device on a mounting
strap. Two cable clamps. Two bare #12 grounding
conductors. What is the minimum cubic inch capacity for
this junction box?
in which hazardous location are open squirrel cage motors Class 1 Division 2
without brushes or centrifugal switches permitted?
Disregard all exceptions
Equipment that is fastened in place has exposed non 8 feet or 96 inches
current carrying metal parts that are likely to become
energized. this equipment shall be grounded if it is within
what minimum vertical distance from the ground or from
grounded metal objects?
according to the NEC, Which of the following statements is equipment must be installed according to the instructions included with the
true about installing listed or labeled equipment? equipment
According to the NEC, a class 1 power limited circuit must 30 volts
be supplied from a source having a rated output of NOT
more than?
Refer to the illustration, what is the minimum dimension of 21 inches
'C'?
an over current protective device for non motorized 10 awg
equipment is rated at 60 amps. What is the minimum
allowable size for copper equipment grounding conductors
for this circuit?
one thirtieth (1/30) of a second is equal to how many hertz 30
Given: Nine (9) size 6 awg type XHHW conductors are in a 37 amps
conduit 50 feet long in a wet location and operate at 110
degrees F. for calculation purposes consider termination as
rated for 75 degrees C. What is the maximum ampacity of
each conductor?
Given : In a normal operation , the load on an overcurrent Answer 80 %
device located in a panelboard will continue for 4 hours .
Disregarding exceptions , the maximum total load allowed
for this circuit is what percent of the circuit overcurrent
device rating ?
Given: a grounding ring consists of 300 feet if bare copper 2 awg
wire encircling a building in direct contact with the earth
and buried 3 feet deep. What minimum size copper wire is
allowed for this grounding ring
Given: only the following type THW conductors are 6 inch x 6 inch
installed in an auxiliary gutter. 8,size 1 awg conductors; 7,
size 2 awg conductors; 4, size 3 awg conductors; 6, size 6
awg conductors. What minimum size auxiliary gutter is
required for these 25 conductors
Refer to the illustration. Each of the supply side emt 4/0 awg
conduits contain three 500 kmil(mcm) copper TH@ service
Conductors. One conductor in each conduit is connected
in parallel for each of three phases. AS shown a separate
bonding jumper is installed from each conduit to the
grounded bus terminal. What is the minimum allowable
size for each copper bonding jumper
Refer to the illustration. This installation requires at least 10
how many sealing fittings
Given: A ground rod Electrode is driven at least 8 feet in to needs to be supplemented by one additional electrode
earth. it's resistance to earth measured at 50 ohms.
According to the NEC, this ground rod electrode:
According to the NEC , electrical junction boxes shall be can be rendered accessible
installed so that the wiring contained in the boxes:
fourteen (14) current carrying conductors are in an 80 foot 50%
conduit run operating at 28 decgrees C or 82 degrees F.
Each conductor shall be derated to what percentage of its'
original ampacity
Refer to the illustration, and the conductor colors of Figure 1, because a white wire can never be used as a switch leg return from the switch to
1 and 2, these figures represent circuits wired with the switched outlet
nonmetallic sheathed cable. Assume all grounding
conductors are installed correctly . which figure is not wired
according to the NEC and why
A metal raceway system is installed in the washing area of 1/4 inch
a car wash. what minimum distance from the surface must
the raceway be mounted?
, National Electrical Code (NEC) | Complete Code Exam Review & Practice Questions | 2026-2027
As long as it has continuity top the grounding electrode Steel conduit
system, an equipment grounding conductor may be a:
Which of the following locations is allowable for bonding the service disconnecting means
the grounding electrode conductor to the grounded
service?
Given: The largest service entrance conductor for a 8 awg
commercial building electrical system with a 100 amp main
circuit breaker is size 1/0 awg aluminum. What is the
minimum allowable copper grounding electrode conductor
for the system?
A remote gasoline pump is located outdoors. Electrical Class 1 Group D division 2
equipment is installed 12 inches above grade and 9 feet
horizontally from the edge of the pump. This electrical
equipment installation is classified as
if the NEC requires that the electrical disconnect switch be 50
placed within sight of the electrical equipment and controls,
the switch must be within how many feet of the equipment
A feeder is supplying a continuous load of 240 amps, it is 500 kcmil
protected by an overcurrent device rated at 300 amps.
Consider terminations rated at 75 degrees C. What
minimum size type of THW aluminum conductors are
allowed as phase conductors for this feeder?
a 120/240 volt single phase panel has a 92 KVA balanced 750 kcmil
incandescent lighting load. The load is in a stock room
which comes on only 2 hours at a time. What is the
minimum size required of each ungrounded aluminum
THW conductor in the feeder circuit to supply this panel
a metal electrical box contains the following; 3 size 12 awg 18.75 cubic inches
conductors, 3 size 10 awg conductors , 1 flush switch, the
switch is connected to two (2) of the size 12 awg
conductors. There are no other devices or fittings. The
cover plate does not have its capacity marked on it. There
are no grounding conductors. All conductors originate
outside the box. What minimum capacity is required for the
metal electrical box containing these conductors and this
switch?
a 120/240 volt 3 phase, 4 wire, power panel which 296.9 amps
supplies all of the following. 1-15 HP, 240 volt, 3 phase
wound rotor motor; 4-5 HP, 240 volt, 3 phase wound rotor
motors; 6-5HP, 240 volt, single phase motors; 3-1 KW, 240
volt, single phase base board heaters; Each ungrounded
conductor in the subfeeder to this power panel has a total
net calculated load of:
Fluorescent lighting fixture each containing 2 ballasts rated 10
0.8 amps each at 120 volts are to be installed for
continuous general lighting in a store. The over current
protection devices are not listed for continuous operation
at 100 percent of their rating. according the the national
electrical code, what is the maximum number of these
lighting fixtures that may be permanently wired to a 20
amp 120 volt branch circuit
an open fixture in a commercial garage shall be placed 12 feet
over vehicular lanes at a height of at least
, National Electrical Code (NEC) | Complete Code Exam Review & Practice Questions | 2026-2027
a park has 35 mobile home sites. the ungrounded wires in 560 amps
the service to supply this park must be calculated size of at
least:
Where an A/C system operating at less than 1000 volts is Serviced disconnecting means
grounded at any point. This systems grounded conductors
shall run to each:
Given : a building has a 120/208 volt, 3 phase service. A it must be connected to the power grounding electrode system
low voltage system that requires a separate grounding
electrode is installed. Which of the following statements
regarding the low voltage system grounding electrode
conductor is true?
What low voltage classification is assigned to a remote class 1
controlled safety control equipment circuit if failure of the
the equipment to operate induces a direct fire or life
hazard?
open overhead service conductors must have horizontal 3 feet
clearance from a porch of at least how many feet?
Given: A surface mounted florescent lighting fixture that 1-1/2 inches
contains a ballast is to be installed on lay-in ceiling tile that
is made of combustible low density cellulose. The fixture is
not approved for direct contact with the material. How far
must this fixture be spaced from the surface of the
fiberboard?
Given: A store lighting branch circuit operates under a 32 amps
continuous load. The branch circuit rating is 40 amps.
What is the maximum continuous load allowed on this
branch circuit?
Given: An explosion proof metal junction box has a 6
capacity of 27 cubic inches and contains a total of 5 size
12 awg wires. Additional conducts of size 10 awg need to
be added to the box. no grounding conductors, devices nor
fittings are contained in the box. What is the maximum
number of additional size 10 awg conductors that may be
added to this box
Given: a 3 phase, squirrel cage motor with full voltage 175%
reactor starting has no code letter. disregard all
exceptions. the dual element time delay fuse used to
proved short circuit protection for this motor branch circuit
should be sized at what maximum percentage of the motor
full load current?
Given: a dispensing station gasoline pump is located class 1 group d division 2
outdoors. Electrical equipment is installed 12 inches above
grade and 9 feet horizontally from the edge of the pump.
This electrical installation sis classified as?
What type of conductor insulation is required for 13 size 3 THWN
awg conductors that are to be installed in a run of 2 inch
metallic tubing
in a dwelling unit a multiwire branch circuit that supplies one double pole circuit breaker
more than one device on the same yoke may be protected
by
, National Electrical Code (NEC) | Complete Code Exam Review & Practice Questions | 2026-2027
Refer to the illustration, disregarding exceptions, what is 30 inches
the minimum width of a clear working space required by
the NEC as noted by 'A'? (*note : 600 volts or less)
a non locking disconnect for 480 volt motor controller must 50 feet
be visible from the controller and within a maximum of how
far from the controller?
Given: A 30 HP wound rotor induction motor with no code 60 amps
letter is to be connected to a 460 volt 3 phase source.
Disregarding all exceptions, what is the maximum rating
allowed for a non timed delay fuse for short circuit
protection of the motor branch circuit?
A building has the following facilities: 25,000 square feet of 100%
office space, 5,500 square feet for a restaurant; 3,000
square feet for an auditorium. what is the general lighting
load feeder demand factor for this building?
an electrical junction box contains only the following : 3, 22.5 cubic inches
#12 insulated conductors entering the box spliced to 3,
#12 conductor leaving the box. one device on a mounting
strap. Two cable clamps. Two bare #12 grounding
conductors. What is the minimum cubic inch capacity for
this junction box?
in which hazardous location are open squirrel cage motors Class 1 Division 2
without brushes or centrifugal switches permitted?
Disregard all exceptions
Equipment that is fastened in place has exposed non 8 feet or 96 inches
current carrying metal parts that are likely to become
energized. this equipment shall be grounded if it is within
what minimum vertical distance from the ground or from
grounded metal objects?
according to the NEC, Which of the following statements is equipment must be installed according to the instructions included with the
true about installing listed or labeled equipment? equipment
According to the NEC, a class 1 power limited circuit must 30 volts
be supplied from a source having a rated output of NOT
more than?
Refer to the illustration, what is the minimum dimension of 21 inches
'C'?
an over current protective device for non motorized 10 awg
equipment is rated at 60 amps. What is the minimum
allowable size for copper equipment grounding conductors
for this circuit?
one thirtieth (1/30) of a second is equal to how many hertz 30
