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Texas Electrician Exams

Texas Journeyman Electrician Practice Test

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70 free Texas Journeyman practice questions with answers

Pick your answer, then open it to see the explanation and the 2026 NEC section.

  1. Definitions, Theory, and Plans

    A building owner wants the main disconnect for a small shop placed where an electrician can reach it. Under the NEC definition, which description matches equipment that is readily accessible?

    1. It can be reached quickly for operation or inspection without climbing over or removing obstacles, using tools other than keys, or using a portable ladder
    2. It admits close approach because it is not guarded by locked doors, elevation or other effective means
    3. It is visible from the equipment it controls and not more than 50 ft away
    4. Its operating handle is no higher than 6 ft 7 in above the floor
    Show answer

    Answer: 1. It can be reached quickly for operation or inspection without climbing over or removing obstacles, using tools other than keys, or using a portable ladder

    Readily accessible is the stricter of the access definitions: ready access must not depend on climbing over or removing obstacles, using tools (other than keys) or using portable ladders. Option 2 describes equipment that is merely approachable because it is not guarded; that is not the readily accessible definition. Option 3 is the meaning of 'in sight from', and option 4 is a maximum handle height for switches and overcurrent devices, not a definition.

    Reference: NEC Article 100 (Accessible, Readily) (NEC 2026)

  2. Electrical Services, Service Equipment, and Separately Derived Systems

    Overhead service-drop conductors of a 120/240-volt, single-phase system pass over the paved driveway of a one-family dwelling. The driveway carries only passenger cars. What is the minimum vertical clearance of the conductors above the driveway?

    1. 10 ft
    2. 12 ft
    3. 15 ft
    4. 18 ft
    Show answer

    Answer: 2. 12 ft

    For systems not over 300 volts to ground, 12 ft applies over residential property and driveways. 10 ft is limited to areas accessible to pedestrians only at not over 150 volts to ground, 15 ft applies where the voltage exceeds 300 volts to ground, and 18 ft applies over public streets, alleys and areas subject to truck traffic.

    Reference: NEC 230.24(B) (NEC 2026)

  3. Electrical Services, Service Equipment, and Separately Derived Systems

    A dwelling has a metal underground water pipe that is in direct contact with the earth for 25 ft, and it is used as a grounding electrode. What else does the NEC require for this grounding electrode system?

    1. Nothing further, because 25 ft of earth contact exceeds the 10 ft minimum
    2. The water pipe must be supplemented by an additional electrode of a type recognized by the Code
    3. The water pipe must be replaced by a concrete-encased electrode
    4. A dielectric union must be installed where the pipe enters the building
    Show answer

    Answer: 2. The water pipe must be supplemented by an additional electrode of a type recognized by the Code

    A metal underground water pipe can serve as an electrode, but the Code always requires it to be supplemented by another recognized electrode (for example a rod or a concrete-encased electrode), because the piping may later be replaced with plastic. A dielectric union would interrupt the electrode path.

    Reference: NEC 250.53(D)(2) (NEC 2026)

  4. Electrical Feeders

    A feeder disconnect rated 1,200 amperes is installed on a solidly grounded 480Y/277-volt system. There is no ground-fault protection of equipment on the supply side of this feeder, and the feeder does not serve a continuous industrial process or a fire pump. What does the NEC generally require at this feeder disconnect?

    1. Ground-fault protection of equipment
    2. A GFCI device for personnel protection
    3. An arc-fault circuit interrupter
    4. No additional protection, because only service disconnects need ground-fault protection
    Show answer

    Answer: 1. Ground-fault protection of equipment

    Feeder disconnects rated 1,000 amperes or more on solidly grounded wye systems of more than 150 volts to ground need ground-fault protection of equipment unless it is already provided on the supply side or an exception applies; a 480Y/277-volt system (277 volts to ground) is inside the covered voltage range. GFCI and AFCI devices protect people and branch circuits, not large feeders.

    Reference: NEC 215.10; NEC 230.95 (NEC 2026)

  5. Electrical Feeders

    A commercial building has both 208Y/120-volt and 480Y/277-volt feeders. How must the ungrounded feeder conductors be identified?

    1. No identification is required if the conductors are in separate raceways
    2. By phase or line and by system at every termination, connection and splice point, with the identification method documented in a readily available form or posted at each feeder panelboard
    3. Only by labeling the voltage on the outside of each raceway every 10 ft
    4. By using black insulation for all 480-volt conductors and red for all 208-volt conductors
    Show answer

    Answer: 2. By phase or line and by system at every termination, connection and splice point, with the identification method documented in a readily available form or posted at each feeder panelboard

    Where more than one nominal voltage system exists, feeder ungrounded conductors are identified by phase or line and by system at all termination, connection and splice points. The Code does not fix a color scheme; the chosen method must be documented where it is readily available or posted at each feeder panelboard.

    Reference: NEC 215.12(C)(2)(a)-(b) (NEC 2026)

  6. Branch Circuits and Conductors

    For a new one-family dwelling built at grade level, what is the minimum outdoor receptacle outlet requirement?

    1. One receptacle outlet anywhere on the exterior
    2. At least one receptacle outlet at the front and one at the back, each readily accessible from grade and not more than 6 1/2 ft above grade
    3. One receptacle outlet on each exterior wall, at any height
    4. Outdoor receptacle outlets are required only where a deck or porch is built
    Show answer

    Answer: 2. At least one receptacle outlet at the front and one at the back, each readily accessible from grade and not more than 6 1/2 ft above grade

    A one-family dwelling at grade needs at least one outdoor receptacle outlet at the front and at the back, readily accessible from grade and not more than 6 1/2 ft above grade. Decks and balconies carry their own separate requirement.

    Reference: NEC 210.52(E)(1) (NEC 2026)

  7. Electrical Wiring Methods and Electrical Materials

    A 35-lb ceiling-suspended paddle fan will be supported only by the outlet box above it. What does the NEC require of that box?

    1. Any metal octagon box may be used if it is 2 1/8 in deep
    2. The box must be listed and marked by the manufacturer as suitable for fan support, and the fan may not exceed the listed weight (70 lb maximum)
    3. A plastic box may be used if it is nailed to a joist
    4. Only a box with an internal volume of at least 30 cubic inches may be used
    Show answer

    Answer: 2. The box must be listed and marked by the manufacturer as suitable for fan support, and the fan may not exceed the listed weight (70 lb maximum)

    A box used as the sole support of a ceiling-suspended fan must be listed and marked as suitable for that purpose, and may not support a fan weighing more than 70 lb (a box for a fan over 35 lb must also be marked with the weight it supports). Depth and volume alone do not qualify a box.

    Reference: NEC 314.27(C) (NEC 2026)

  8. Electrical Wiring Methods and Electrical Materials

    A run of rigid metal conduit is installed exposed along a warehouse wall. The run is not a straight run made up with threaded couplings, so the longer spans of the 344.30(B) table do not apply. Apart from the securing requirement near boxes, at what maximum interval must it be supported?

    1. 4 1/2 ft
    2. 8 ft
    3. 10 ft
    4. 14 ft
    Show answer

    Answer: 3. 10 ft

    Rigid metal conduit is supported at intervals not exceeding 10 ft and securely fastened within 3 ft of each outlet box, junction box, cabinet or conduit termination. Longer spans (such as 14 ft) are permitted only for straight runs made up with threaded couplings under the table in 344.30(B), which the stem excludes.

    Reference: NEC 344.30(A) and (B) (NEC 2026)

  9. Electrical Equipment and Devices

    A new wall switch in a dwelling bedroom controls the ceiling luminaire, which is supplied by a grounded general-purpose branch circuit. The cable enters the switch box through a finished wall and is not in a raceway, and the lighting is not controlled by any automatic means. What does the NEC generally require at the switch location?

    1. A grounded (neutral) conductor for the circuit
    2. A GFCI device
    3. A second equipment grounding conductor
    4. A locking means for the switch
    Show answer

    Answer: 1. A grounded (neutral) conductor for the circuit

    Where switches control lighting loads supplied by a grounded general-purpose branch circuit serving bathrooms, hallways, stairways and habitable rooms, the grounded conductor must be installed at the switch location. It is not required where the conductors enter through a raceway large enough to add it, where snap switches with integral enclosures are used, where the lighting is controlled from a remote control location, or where the switch controls a receptacle load, and an exception covers certain replacement switches; none applies to this new bedroom switch. The rule supports electronic switches such as occupancy sensors and timers.

    Reference: NEC 406.30(C) (404.2(C) in the 2023 NEC) (NEC 2026)

  10. Electrical Equipment and Devices

    In a bathroom, which of these installations is not permitted?

    1. A cord-suspended pendant luminaire hanging 2 ft horizontally from the bathtub rim and 6 ft above it
    2. A recessed luminaire in the ceiling 9 ft above the bathtub rim
    3. A wall-mounted luminaire 5 ft horizontally from the bathtub rim
    4. A luminaire over the vanity basin, away from the tub and shower
    Show answer

    Answer: 1. A cord-suspended pendant luminaire hanging 2 ft horizontally from the bathtub rim and 6 ft above it

    Cord-connected luminaires, chain-, cable- or cord-suspended luminaires, lighting track and pendants may not be located within the zone 3 ft horizontally and 8 ft vertically from the top of the bathtub rim or shower threshold. The pendant in option 1 is inside that zone; the others are outside it.

    Reference: NEC 410.10(D) (NEC 2026)

  11. Motors and Generators

    A motor disconnect is required to be in sight from the motor. What does 'in sight from' mean under the NEC?

    1. The disconnect is in the same room, at any distance
    2. The disconnect is visible from the motor and not more than 50 ft away
    3. The disconnect is within 25 ft, even if a wall blocks the view
    4. The disconnect can be seen on a camera monitor at the motor
    Show answer

    Answer: 2. The disconnect is visible from the motor and not more than 50 ft away

    'In sight from' means that one piece of equipment is visible from the other and not more than 50 ft distant. Distance alone, or a camera image, does not satisfy it.

    Reference: NEC 110.29 (NEC 2026)

  12. Electrical Control Devices and Disconnecting Means

    A three-phase motor disconnect is being selected. Which design meets the NEC operating requirements for a motor disconnecting means?

    1. It opens all ungrounded supply conductors at once, and no pole can be operated independently
    2. It opens one ungrounded conductor, since that stops the motor
    3. It uses three single-pole switches, one for each phase
    4. It opens only the grounded conductor
    Show answer

    Answer: 1. It opens all ungrounded supply conductors at once, and no pole can be operated independently

    The motor disconnecting means must open all ungrounded supply conductors and be designed so that no pole can be operated independently. Opening one phase can single-phase the motor and leaves parts energized.

    Reference: NEC 430.103 (NEC 2026)

  13. Special Occupancies, Equipment, and Conditions

    At a solvent dip tank, ignitable concentrations of flammable vapors can exist under normal operating conditions. How is this location classified?

    1. Class I, Division 1
    2. Class I, Division 2
    3. Class II, Division 1
    4. Class III, Division 2
    Show answer

    Answer: 1. Class I, Division 1

    Class I covers flammable gases and vapors. Division 1 applies where ignitable concentrations can exist under normal operating conditions, which is exactly the condition the stem describes at the dip tank, so Division 2 is not the classification here. Class II is combustible dust and Class III is ignitable fibers.

    Reference: NEC 500.5(B)(1) (NEC 2026)

  14. Renewable Energy Technologies

    Where must the PV system disconnecting means for a rooftop solar system on a house be installed?

    1. At a readily accessible location
    2. On the roof, next to the modules only
    3. Inside the attic, near the inverter
    4. Anywhere, if a label identifies it
    Show answer

    Answer: 1. At a readily accessible location

    The PV system disconnecting means must be installed at a readily accessible location so it can be operated without ladders or removing obstacles. Labels are required too, but they do not replace the location rule.

    Reference: NEC 690.13 and 705.20 (2026 harmonized disconnect rules) (NEC 2026)

  15. Electrical Services, Service Equipment, and Separately Derived Systems

    Using the 2026 optional calculation for a one-family dwelling, the general loads total 36,000 VA. The first 8,000 VA of the general loads is taken at 100% and the remainder at 40%. The air-conditioning load of 6,000 VA is then added at 100%. What is the calculated load in amperes on a 120/240-volt, single-phase service?

    1. 70 A
    2. 80 A
    3. 90 A
    4. 105 A
    Show answer

    Answer: 4. 105 A

    The general loads demand 8,000 + 0.4 x 28,000 = 19,200 VA; adding 6,000 VA for the air conditioner gives 25,200 VA, and 25,200 / 240 = 105 A. 70 A applies 40% to everything. 80 A leaves out the air conditioner. 90 A puts the air conditioner inside the 40% step.

    Reference: NEC 120.82(B) and 120.82(C)(1) (220.82 in the 2023 NEC) (NEC 2026)

  16. Branch Circuit Calculations and Conductors

    A conference center (not a dwelling) has 6 single-gang boxes, each with one duplex receptacle on one yoke; 3 two-gang boxes, each with two duplex receptacles on two separate yokes; and 1 single receptacle on its own yoke. Each single or multiple receptacle on one yoke is counted at 180 VA. What receptacle load is calculated?

    1. 1,170 VA
    2. 1,800 VA
    3. 2,340 VA
    4. 4,500 VA
    Show answer

    Answer: 3. 2,340 VA

    The yokes are 6 + (3 x 2) + 1 = 13, and 13 x 180 = 2,340 VA. 1,170 VA takes 50% of the correct load. 1,800 VA counts each box as one yoke. 4,500 VA counts every receptacle separately.

    Reference: NEC 120.14(I) (NEC 2026)

  17. Electrical Feeders

    A feeder carries 90 amperes of continuous load and 40 amperes of noncontinuous load. The overcurrent device is not rated for continuous operation at 100%, all terminations are rated 75 degrees C, and no correction or adjustment factors apply. Use these 75 degrees C copper ampacities: 1 AWG 130 A, 1/0 AWG 150 A, 2/0 AWG 175 A, 3/0 AWG 200 A. What is the smallest copper conductor that may be used?

    1. 1 AWG
    2. 1/0 AWG
    3. 2/0 AWG
    4. 3/0 AWG
    Show answer

    Answer: 3. 2/0 AWG

    The conductor must carry the noncontinuous load plus 125% of the continuous load, which is 40 + 1.25 x 90 = 152.5 A, and the smallest listed conductor with at least 152.5 A at 75 degrees C is 2/0 AWG at 175 A. 1 AWG carries 130 A, which is only the plain 90 + 40 total with no 125% on the continuous load. 1/0 AWG carries 150 A, which comes from applying 125% to the noncontinuous load instead of the continuous load. 3/0 AWG carries 200 A, which comes from applying 125% a second time to the 152.5 A result.

    Reference: NEC 215.4(A)(1) (215.2(A)(1) in the 2023 NEC) and 110.14(C)(1)(b) (NEC 2026)

  18. Motors and Generators

    A 15-horsepower, 230-volt, three-phase, continuous-duty motor has a table full-load current of 42 amperes. Its nameplate shows a full-load current of 39 amperes and a service factor of 1.15. What are the minimum branch-circuit conductor ampacity and the maximum rating of a separate overload device under the basic overload rule?

    1. 42.0 A conductors; 48.8 A overload
    2. 48.8 A conductors; 48.8 A overload
    3. 52.5 A conductors; 44.9 A overload
    4. 52.5 A conductors; 48.8 A overload
    Show answer

    Answer: 4. 52.5 A conductors; 48.8 A overload

    Conductors are sized from the table current: 42 x 1.25 = 52.5 A. Separate overloads are sized from the nameplate current, and a 1.15 service factor allows 125%: 39 x 1.25 = 48.75 A. 42.0 A conductors; 48.8 A overload sizes the conductors at the table current without the 125% factor. 48.8 A conductors; 48.8 A overload uses the nameplate current for the conductors as well. 52.5 A conductors; 44.9 A overload uses 115% for the overload, which is for motors without a 1.15 service factor or a 40 C rise.

    Reference: NEC 430.6(A)(1), 430.22 and 430.32(A)(1) (NEC 2026)

  19. Renewable Energy Technologies

    Four 240-volt EV charger branch circuits share one raceway in a parking garage, so the raceway holds 8 current-carrying THHN copper conductors (adjustment factor 0.70), and the ambient correction factor for the 90 degree C column is 0.91. Each charger draws 48 A continuously. The conductors must carry 125% of the load at the 75 degree C terminals and must also carry the load after correction and adjustment. Copper ampacities (75 C / 90 C): 8 AWG 50 / 55 A; 6 AWG 65 / 75 A; 4 AWG 85 / 95 A; 3 AWG 100 / 115 A. What is the smallest conductor for each charger circuit?

    1. 8 AWG
    2. 6 AWG
    3. 4 AWG
    4. 3 AWG
    Show answer

    Answer: 3. 4 AWG

    At the terminals each circuit needs 1.25 x 48 = 60 A, which 6 AWG (65 A) meets. After the factors 6 AWG gives only 75 x 0.91 x 0.7 = 47.78 A, which is just below 48 A, while 4 AWG gives 95 x 0.91 x 0.7 = 60.5 A. 8 AWG uses the 48 A load without the 125% factor or the derating factors. 6 AWG makes only the 125% terminal check. 3 AWG applies both factors to the 125% value at the 75 C column.

    Reference: NEC 210.19, 310.15(B), 310.15(C)(1) and Article 625 (EV charging as a continuous load) (NEC 2026)

  20. Electrical Wiring Methods and Electrical Materials

    A trade size 3/4 EMT (total internal area 0.533 square inch, 40% fill for more than two conductors) is filled with the maximum number of 12 AWG THHN copper conductors (0.0133 square inch each), all current-carrying. 12 AWG THHN is rated 30 A at 90 degrees C; adjustment factors: 7-9 conductors 0.70; 10-20 conductors 0.50. Small-conductor rule: 12 AWG copper not over 20 A. No ambient correction applies. Standard ratings: 15, 20, 25, 30 A. What is the largest overcurrent device that may protect each conductor?

    1. 15 A
    2. 20 A
    3. 25 A
    4. 30 A
    Show answer

    Answer: 1. 15 A

    40% of 0.533 is 0.2132 square inch, which holds 16.03, so 16 conductors. With 16 current-carrying conductors the factor is 0.50, so each conductor is rated 30 x 0.50 = 15 A; 15 A is a standard rating, so the device may not exceed 15 A even though the small-conductor rule alone would allow 20 A. 20 A applies only the small-conductor limit and skips the adjustment for the conductor count. 25 A uses the 0.70 factor for 7-9 conductors and rounds up. 30 A uses the 90 C ampacity with no adjustment.

    Reference: NEC Chapter 9, Table 1, Chapter 9, Table 4, Chapter 9, Table 5, 310.15(C)(1) and 240.4(D) (NEC 2026)

  21. Definitions, Theory, and Plans

    Under the NEC definition, a branch circuit is made up of which conductors?

    1. The circuit conductors between the final overcurrent device protecting the circuit and the outlets
    2. The conductors from the utility transformer to the service point
    3. The conductors between the service equipment and the final branch-circuit overcurrent device
    4. Only the conductors inside a luminaire
    Show answer

    Answer: 1. The circuit conductors between the final overcurrent device protecting the circuit and the outlets

    A branch circuit runs from the final overcurrent device protecting the circuit to the outlets. The conductors between the service equipment and the final branch-circuit overcurrent device are a feeder.

    Reference: NEC Article 100 (Branch Circuit) (NEC 2026)

  22. Electrical Services, Service Equipment, and Separately Derived Systems

    For a grounded separately derived system, where is the grounding electrode conductor connected to the grounded conductor?

    1. At any convenient point downstream of the first disconnect
    2. At every panelboard supplied by the system
    3. At the same point on the separately derived system where the system bonding jumper is connected
    4. Only at the building service
    Show answer

    Answer: 3. At the same point on the separately derived system where the system bonding jumper is connected

    The grounding electrode conductor connects to the grounded conductor at the same point where the system bonding jumper is connected, so the neutral is bonded and grounded in one place.

    Reference: NEC Article 250 (separately derived systems) (NEC 2026)

  23. Electrical Feeders

    Several 125-volt, 15- and 20-ampere receptacle branch circuits require GFCI protection for personnel. May that protection be provided instead by a GFCI that protects the feeder supplying them?

    1. No, GFCI devices may only be on branch circuits
    2. Only for 240-volt circuits
    3. Only in dwelling units
    4. Yes, a listed GFCI installed in a readily accessible location may protect the feeder in place of GFCI protection on each branch circuit
    Show answer

    Answer: 4. Yes, a listed GFCI installed in a readily accessible location may protect the feeder in place of GFCI protection on each branch circuit

    A feeder supplying 15- and 20-ampere receptacle branch circuits may be protected by a listed GFCI installed in a readily accessible location, in lieu of the GFCI protection that the referenced GFCI rules would otherwise require on those branch circuits. The permission stands in only for those referenced GFCI provisions, not for other protection requirements. GFCI protection is not limited to branch-circuit devices, and the permission is not limited to 240-volt circuits or to dwelling units.

    Reference: NEC 215.9 (NEC 2026)

  24. Branch Circuits and Conductors

    An electrician needs to mount a panel on a concrete block wall. Which of these is not an acceptable way to fasten the equipment?

    1. Masonry anchors
    2. Expansion bolts
    3. Wooden plugs driven into holes in the masonry
    4. Toggle bolts in hollow block
    Show answer

    Answer: 3. Wooden plugs driven into holes in the masonry

    Equipment must be firmly secured, and wooden plugs driven into masonry, concrete, plaster or similar materials are not acceptable. Masonry anchors, expansion bolts and toggle bolts are all accepted ways to fasten equipment.

    Reference: NEC Article 110 (mounting of equipment) (NEC 2026)

  25. Electrical Wiring Methods and Electrical Materials

    An electrician plans to support a raceway above a suspended ceiling by wrapping it to the ceiling grid support wires. Is this acceptable?

    1. Yes, because any ceiling grid support wire may also carry a raceway or cable
    2. No. The raceway needs its own support; separate support wires installed in addition to the ceiling grid wires and distinguishable from them may be used
    3. Yes, if the raceway and its conductors weigh less than 20 pounds in total
    4. Yes, if the raceway is EMT and is strapped tightly to the support wire
    Show answer

    Answer: 2. No. The raceway needs its own support; separate support wires installed in addition to the ceiling grid wires and distinguishable from them may be used

    Ceiling grid support wires may not be used as the support for raceways or cables unless separate support wires are installed and clearly distinguished for that purpose. Weight or raceway type does not change the rule.

    Reference: NEC Article 300 (securing and supporting; ceiling support wires) (NEC 2026)

  26. Electrical Equipment and Devices

    Which information must appear on the nameplate of an appliance?

    1. The identifying name and the rating in volts and amperes or volts and watts
    2. The installer license number and the permit date for the installation job
    3. The purchase date and the retail store location where it was bought
    4. The utility rate class and the name of the account holder at the address
    Show answer

    Answer: 1. The identifying name and the rating in volts and amperes or volts and watts

    Each appliance nameplate must give the identifying name and the rating in volts and amperes, or in volts and watts (and the frequency where the appliance is for a specific frequency). Installer and purchase details are not nameplate items.

    Reference: NEC 422.60(A) (NEC 2026)

  27. Motors and Generators

    One side of a motor control circuit is grounded. How must the control circuit be arranged with respect to an accidental ground in the control circuit remote from the motor controller?

    1. So that the fault starts the motor
    2. So that the fault reverses the motor
    3. So that the fault resets the overload
    4. So that the fault does not start the motor or bypass manually operated or automatic safety shutdown devices
    Show answer

    Answer: 4. So that the fault does not start the motor or bypass manually operated or automatic safety shutdown devices

    Where one side of the control circuit is grounded, the circuit is arranged so an accidental ground in the control circuit remote from the motor controller will not start the motor and will not bypass manually operated or automatic safety shutdown devices. Starting, reversing or resetting are the unsafe results the rule prevents.

    Reference: NEC Article 430 (motor control circuits) (NEC 2026)

  28. Electrical Control Devices and Disconnecting Means

    What is the main difference between a magnetic contactor and a magnetic motor starter?

    1. A starter does not have an operating coil, but a contactor does
    2. A contactor includes thermal overloads, but a starter does not
    3. A starter is used only on dc circuits and a contactor only on ac
    4. A starter includes overload relays and a contactor does not
    Show answer

    Answer: 4. A starter includes overload relays and a contactor does not

    A motor starter is a contactor combined with overload protection. A contactor only makes and breaks the circuit, and both use a coil.

    Reference: Electrical control (contactors and starters); no NEC section applies (NEC 2026)

  29. Special Occupancies, Equipment, and Conditions

    How must emergency lighting be arranged so that the failure of one lighting element does not cause what?

    1. Any space that requires emergency illumination to be left in total darkness
    2. A breaker to trip
    3. The generator to start
    4. The fire alarm to sound
    Show answer

    Answer: 1. Any space that requires emergency illumination to be left in total darkness

    Emergency lighting is arranged so the failure of any single lighting element, such as a burned-out lamp, cannot leave an area that needs emergency illumination in total darkness.

    Reference: NEC Article 700 (emergency illumination) (NEC 2026)

  30. Renewable Energy Technologies

    An energy storage system is installed. What does it need for its ungrounded output conductors?

    1. No disconnecting means
    2. Only a fuse in the battery
    3. A disconnecting means for all ungrounded conductors derived from the energy storage system
    4. Only a GFCI receptacle
    Show answer

    Answer: 3. A disconnecting means for all ungrounded conductors derived from the energy storage system

    An energy storage system has a disconnecting means for all ungrounded conductors derived from it, so it can be isolated for service or emergencies.

    Reference: NEC Article 706 (disconnecting means) (NEC 2026)

  31. Definitions, Theory, and Plans

    Under the NEC definition, which conductors make up a feeder?

    1. The conductors between an outlet and the utilization equipment
    2. The conductors between the utility pole and the meter
    3. Only the grounded conductors of a service
    4. All circuit conductors between the service equipment, the source of a separately derived system or other power supply source, and the final branch-circuit overcurrent device
    Show answer

    Answer: 4. All circuit conductors between the service equipment, the source of a separately derived system or other power supply source, and the final branch-circuit overcurrent device

    A feeder runs from the service equipment, a separately derived system or another power source to the final branch-circuit overcurrent device. Past that device the conductors are a branch circuit.

    Reference: NEC Article 100 (Feeder) (NEC 2026)

  32. Electrical Services, Service Equipment, and Separately Derived Systems

    A service main bonding jumper is a screw only. How must the screw be identified?

    1. With a red finish
    2. With a white finish
    3. With a green finish that is visible with the screw installed
    4. No identification is needed
    Show answer

    Answer: 3. With a green finish that is visible with the screw installed

    Where the main bonding jumper is a screw only, the screw is identified with a green finish that shall be visible with the screw installed.

    Reference: NEC Article 250 (main bonding jumper construction) (NEC 2026)

  33. Electrical Feeders

    Feeder tap conductors not over 10 feet long are installed under the 10-foot tap rule. Which requirement applies to them?

    1. The tap conductors must not extend beyond the switchboard, panelboard or control device they supply
    2. The tap conductors must be at least one-third of the rating of the feeder overcurrent device
    3. The tap conductors must end in a fused disconnect rated higher than the feeder device
    4. The tap conductors may continue outdoors without enclosure as long as they are 10 feet or less
    Show answer

    Answer: 1. The tap conductors must not extend beyond the switchboard, panelboard or control device they supply

    Under the 10-foot tap rule, the tap conductors must not extend beyond the equipment they supply. Where field-installed tap conductors leave the enclosure or vault in which the tap is made, their ampacity must be at least one-tenth of the feeder overcurrent device rating. One-third belongs to the 25-foot tap rule.

    Reference: NEC 240.21(B)(1) (NEC 2026)

  34. Electrical Wiring Methods and Electrical Materials

    A ferrous metal raceway is installed in direct contact with the earth. What does the NEC require?

    1. Nothing, because the steel wall is thick enough to resist any kind of soil
    2. Only a coat of ordinary paint applied to the outside of the raceway
    3. Only a protective coating applied to the inside surface of the raceway
    4. It must be suitable for the conditions or have approved corrosion protection
    Show answer

    Answer: 4. It must be suitable for the conditions or have approved corrosion protection

    Ferrous raceways in soil need corrosion protection or must be identified for the condition. Ordinary paint or interior coating does not protect the outer surface.

    Reference: NEC Article 300 (corrosion protection of ferrous raceways) (NEC 2026)

  35. Electrical Equipment and Devices

    In a clothes closet, which volume is the storage space for the purpose of luminaire clearances?

    1. Floor to 6 ft (or the highest rod) within 24 in of the walls, then 12 in or the shelf width above
    2. Only the volume within 6 inches of the hanging rod, from the rod down to the closet floor
    3. Only the volume above the highest shelf, up to the ceiling and across the full closet width
    4. Only the volume within 12 inches of the ceiling, measured across the full depth of the closet
    Show answer

    Answer: 1. Floor to 6 ft (or the highest rod) within 24 in of the walls, then 12 in or the shelf width above

    Closet storage space runs from the floor up to 6 feet or the highest clothes rod, within 24 inches of the side and back walls, and then continues up to the ceiling within 12 inches of the walls or the width of the shelf, whichever is greater. The other volumes leave out most of the space where clothing and stored items sit.

    Reference: NEC 410.16(A) (NEC 2026)

  36. Motors and Generators

    At a one-family dwelling, a permanently installed 22 kW standby generator (not cord-and-plug connected) is installed. Where must its emergency shutdown device be located?

    1. Outside the dwelling at a readily accessible location
    2. Inside the generator enclosure only
    3. In the basement
    4. At the utility meter only
    Show answer

    Answer: 1. Outside the dwelling at a readily accessible location

    At one- and two-family dwellings, generators other than cord-and-plug-connected portable units have an emergency shutdown device outside the dwelling at a readily accessible location, so first responders can shut them down without going inside. A device only inside the generator enclosure, in the basement or at the meter does not meet the rule.

    Reference: NEC Article 445 (emergency shutdown, one- and two-family dwellings) (NEC 2026)

  37. Electrical Control Devices and Disconnecting Means

    What does it mean when a circuit breaker is described as trip-free?

    1. It never trips on overloads, only on short circuits and faults
    2. It trips only while the handle is being held in the ON position
    3. It needs no overcurrent element because the handle does the work
    4. It will trip even if the handle is held in the ON position
    Show answer

    Answer: 4. It will trip even if the handle is held in the ON position

    A trip-free breaker opens on overcurrent even if the handle is held closed, so the handle cannot be forced to defeat protection. It still has overcurrent elements.

    Reference: Electrical theory (trip-free circuit breaker operation); no NEC section applies (NEC 2026)

  38. Special Occupancies, Equipment, and Conditions

    What are optional standby systems intended to supply?

    1. Loads that the Code requires to have emergency power
    2. Only exit signs
    3. Only fire pumps
    4. Loads such as industrial processes or homes where power is wanted during an outage but is not required by code
    Show answer

    Answer: 4. Loads such as industrial processes or homes where power is wanted during an outage but is not required by code

    Optional standby systems supply loads that the owner chooses to back up, such as home circuits or industrial processes, where a code does not require standby power.

    Reference: NEC Article 702 (optional standby systems) (NEC 2026)

  39. Renewable Energy Technologies

    A building has a utility service and a PV system. What is required at the service equipment?

    1. Nothing
    2. A permanent plaque or directory identifying the power sources and the location of their disconnecting means
    3. Only a sticker on the meter
    4. Only a note in the permit file
    Show answer

    Answer: 2. A permanent plaque or directory identifying the power sources and the location of their disconnecting means

    A permanent plaque or directory at the service equipment shows that the building has more than one power source and where each source can be disconnected.

    Reference: NEC Article 690 (identification of power sources) (NEC 2026)

  40. Definitions, Theory, and Plans

    Which conductor is the conductive path that connects normally non-current-carrying metal parts of equipment to the system grounded conductor, the grounding electrode conductor or both?

    1. The equipment grounding conductor
    2. The branch-circuit grounded neutral
    3. The ungrounded circuit conductor
    4. The feeder supply conductor
    Show answer

    Answer: 1. The equipment grounding conductor

    The equipment grounding conductor provides the ground-fault current path back to the source and connects the metal parts. The other options are ordinary current-carrying conductors, not the defined term.

    Reference: NEC Article 100 (Grounding Conductor, Equipment) (NEC 2026)

  41. Electrical Services, Service Equipment, and Separately Derived Systems

    At service equipment, a metal raceway enters a concentric knockout with some rings removed. What must be done to bond the raceway?

    1. Nothing; the locknut is enough
    2. Install a plastic bushing only
    3. Paint the knockout
    4. Use a bonding jumper or other listed bonding means around the impaired connection
    Show answer

    Answer: 4. Use a bonding jumper or other listed bonding means around the impaired connection

    At services, a connection through concentric or eccentric knockouts that are punched or otherwise formed so as to impair the connection is not relied on for bonding; a bonding jumper or other listed means is used.

    Reference: NEC Article 250 (bonding at services) (NEC 2026)

  42. Electrical Feeders

    A feeder disconnect rated 1,200 amperes on a solidly grounded 480Y/277-volt system supplies a continuous industrial process where a nonorderly shutdown would create additional hazards. What does the NEC allow regarding ground-fault protection of equipment?

    1. Ground-fault protection of equipment is not required for that disconnect
    2. It must be installed and set to trip instantly on any ground fault
    3. It must be installed with a pickup setting of 3,000 amperes or more
    4. It is required only where the feeder runs longer than 100 feet
    Show answer

    Answer: 1. Ground-fault protection of equipment is not required for that disconnect

    Continuous industrial processes where a nonorderly shutdown would introduce hazards are an exception to the ground-fault protection rule for feeder disconnects. The other options invent conditions that are not in the rule.

    Reference: NEC 215.10 (NEC 2026)

  43. Electrical Wiring Methods and Electrical Materials

    What must be provided between the conductors and the armor at the end of Type AC cable?

    1. A copper bonding wire wrapped back over the armor with a clamp
    2. An insulating bushing or an armor connector with an insulated throat
    3. A layer of electrical tape wrapped over the cut armor only
    4. Nothing, since the armor is grounded through the connector
    Show answer

    Answer: 2. An insulating bushing or an armor connector with an insulated throat

    The cut armor edge can cut the conductor insulation, so an insulating bushing or an armor connector with an insulated throat is required. Tape alone is not adequate, and grounding does not prevent cutting.

    Reference: NEC Article 320 (armored cable fittings) (NEC 2026)

  44. Motors and Generators

    A three-phase induction motor runs in the wrong direction. What is the simplest way to reverse it?

    1. Swap the grounded and grounding conductors
    2. Change the overload heaters
    3. Rotate all three line conductors one position (L1 to L2, L2 to L3, L3 to L1)
    4. Interchange any two of the three line conductors
    Show answer

    Answer: 4. Interchange any two of the three line conductors

    Interchanging any two line conductors reverses the phase sequence and the direction of rotation. Rotating all three conductors one position keeps the same phase sequence, so the motor keeps running the same way.

    Reference: Motor theory (phase rotation); no NEC section applies (NEC 2026)

  45. Electrical Control Devices and Disconnecting Means

    How does an inverse time circuit breaker respond to overcurrent?

    1. The higher the current, the longer the time to trip
    2. It trips at the same time at every current
    3. The higher the current, the shorter the time to trip
    4. It trips only on voltage
    Show answer

    Answer: 3. The higher the current, the shorter the time to trip

    An inverse time breaker has a time delay that shortens as current rises, allowing brief inrush and tripping quickly on large faults. It does not trip at a constant time.

    Reference: NEC Article 100 (Circuit Breaker, Inverse Time) (NEC 2026)

  46. Special Occupancies, Equipment, and Conditions

    At a motor fuel dispensing facility, what must the disconnecting means for each circuit leading to or through dispensing equipment open?

    1. Only the ungrounded conductors
    2. All conductors of the circuit, including the grounded conductor
    3. Only the equipment grounding conductor
    4. Only the control circuit
    Show answer

    Answer: 2. All conductors of the circuit, including the grounded conductor

    Circuits to fuel dispensers are disconnected on all conductors, including the grounded conductor, so no conductor in the hazardous area stays connected during maintenance.

    Reference: NEC Article 514 (circuit disconnects at motor fuel dispensing facilities) (NEC 2026)

  47. Renewable Energy Technologies

    A PV inverter is connected to a panelboard through a backfed circuit breaker. Which warning is typically required at that breaker?

    1. A label stating the panelboard serial number and its date of manufacture
    2. A tag marking the breaker as a spare reserved for future circuit use
    3. A warning label that it is a power source output and must not be relocated
    4. No warning label, because a listed backfed breaker needs no marking
    Show answer

    Answer: 3. A warning label that it is a power source output and must not be relocated

    A permanent warning label tells future workers that the backfed breaker is a power source output connection and must not be moved, because relocating it could overload the busbar. A serial number or spare tag would be misleading, and being listed does not remove the marking requirement.

    Reference: NEC 705.12(B)(2)(b) (NEC 2026)

  48. Definitions, Theory, and Plans

    Which change lowers the resistance of a copper conductor of a given length?

    1. Using a conductor with a smaller circular-mil area
    2. Substituting a material that is a poorer conductor
    3. Doubling the length of the conductor
    4. Using a conductor with a larger cross-sectional area
    Show answer

    Answer: 4. Using a conductor with a larger cross-sectional area

    Resistance falls as cross-sectional area increases and rises with length. A smaller area or a longer run raises resistance, and a poorer conductor material also raises it.

    Reference: Electrical theory (conductor resistance); no NEC section applies (NEC 2026)

  49. Electrical Services, Service Equipment, and Separately Derived Systems

    Where must the overcurrent device protecting service conductors be located relative to the service disconnecting means?

    1. At the utility meter, outside the building on the pole side
    2. Anywhere within 25 feet of the service disconnecting means
    3. At the first panelboard on the load side, wherever that panel is
    4. Integral with the disconnecting means or immediately adjacent to it
    Show answer

    Answer: 4. Integral with the disconnecting means or immediately adjacent to it

    The service overcurrent device is part of, or immediately next to, the service disconnect, so the conductors are protected as soon as they enter the equipment. Placing it at the meter, at a distant panel or within 25 feet does not meet the rule.

    Reference: NEC Article 230 (service overcurrent protection location) (NEC 2026)

  50. Electrical Feeders

    For what use are Edison-base plug fuses permitted?

    1. In all new dwelling-unit panelboards for circuits of 15 amperes or less
    2. Only as replacements in existing installations with no evidence of tampering
    3. Only for circuits of 40 amperes and larger in industrial occupancies
    4. In any installation as long as the fuse is a dual-element type
    Show answer

    Answer: 2. Only as replacements in existing installations with no evidence of tampering

    Edison-base fuses may only replace existing ones where nothing indicates tampering or overfusing. New installations use Type S fuses with adapters that prevent a larger fuse from being installed.

    Reference: NEC Article 240 (plug fuses) (NEC 2026)

  51. Electrical Wiring Methods and Electrical Materials

    A plug-in circuit breaker in a panelboard is backfed to terminate field-installed supply conductors. What additional means is required?

    1. An additional fastener that needs more than a pull to release the breaker
    2. A second main breaker installed on the incoming supply conductors
    3. A label giving the installer name, license number and installation date
    4. Nothing more, because the breaker clips hold it firmly enough in place
    Show answer

    Answer: 1. An additional fastener that needs more than a pull to release the breaker

    A backfed plug-in device used to terminate supply conductors must be secured by an extra fastener that needs more than a pull to release, so it cannot be pulled off live conductors. Clips alone can release.

    Reference: NEC Article 408 (backfed devices in panelboards) (NEC 2026)

  52. Motors and Generators

    Which information must be on a generator nameplate?

    1. The date of installation and the name of the building owner
    2. The rating in kilowatts or kilovolt-amperes and the power factor
    3. The name and license number of the electrician who connected it
    4. The fuel tank capacity and the expected full-load run time
    Show answer

    Answer: 2. The rating in kilowatts or kilovolt-amperes and the power factor

    A generator nameplate gives manufacturer name, rated frequency, phases, kW or kVA rating, power factor, volts and amperes, and temperature information. Installation date, electrician and tank size are not required.

    Reference: NEC Article 445 (generator nameplate) (NEC 2026)

  53. Electrical Control Devices and Disconnecting Means

    How does the rating of a general-use switch differ from that of a motor-circuit switch?

    1. A general-use switch is rated in amperes, and a motor-circuit switch is rated in horsepower
    2. A general-use switch is rated in horsepower, and a motor-circuit switch in amperes
    3. Both are rated in volts only
    4. Neither has a rating
    Show answer

    Answer: 1. A general-use switch is rated in amperes, and a motor-circuit switch is rated in horsepower

    A general-use switch is rated in amperes and must interrupt its rated current at rated voltage. A motor-circuit switch is rated in horsepower and must interrupt the maximum operating overload current of a motor of the same horsepower rating at rated voltage. The ratings are not reversed.

    Reference: NEC Article 100 (Switch, General-Use; Switch, Motor-Circuit) and Article 404 (NEC 2026)

  54. Special Occupancies, Equipment, and Conditions

    Where must the disconnecting means for an electric sign generally be located?

    1. Anywhere in the building
    2. Inside the sign body only
    3. Only at the service
    4. Within sight of the sign, or lockable in the open position where not within sight
    Show answer

    Answer: 4. Within sight of the sign, or lockable in the open position where not within sight

    Each sign has a disconnecting means within sight of the sign, or a disconnect that can be locked in the open position where it is not within sight, so a worker on the sign controls the power.

    Reference: NEC Article 600 (sign disconnecting means) (NEC 2026)

  55. Renewable Energy Technologies

    PV string circuits are connected in parallel through a dc combiner. In which case does the 2026 NEC generally require overcurrent protection for these PV source circuits?

    1. Where the current from all sources that can feed a fault, including the other parallel strings, exceeds the module's maximum overcurrent device rating
    2. Only where a single series string feeds the inverter
    3. Only where the modules are the monocrystalline type
    4. Never, since PV source circuits are current limited
    Show answer

    Answer: 1. Where the current from all sources that can feed a fault, including the other parallel strings, exceeds the module's maximum overcurrent device rating

    Under 690.9(A)(1), overcurrent devices are not required where the conductors are sized for the maximum circuit current and the current from all sources does not exceed the module's maximum overcurrent device rating. When the current that the other parallel strings and sources can feed into a fault exceeds that rating, protection is required. The Code does not count strings: three or more strings in parallel is a common result of this test, not the rule. A single series string has no other parallel strings feeding it, module type does not matter, and PV source circuits are not exempt just because each module's current is limited.

    Reference: NEC 690.9(A)(1) (NEC 2026)

  56. Calculations and Theory

    A plant load of 50 kilowatts runs at a power factor of 0.80 lagging. Capacitors will raise the power factor to 0.95. The tangent of the power-factor angle is 0.750 at 0.80 and 0.3287 at 0.95. How many kVAR of capacitors are needed, to the nearest 0.1 kVAR?

    1. 7.5 kVAR
    2. 21.1 kVAR
    3. 37.5 kVAR
    4. 53.9 kVAR
    Show answer

    Answer: 2. 21.1 kVAR

    The capacitors must remove the difference in reactive power: 50 x (0.750 - 0.3287) = 21.065 kVAR, or 21.1 kVAR. 7.5 kVAR multiplies the power-factor difference by the kilowatts. 37.5 kVAR supplies all of the original reactive power, which would take the power factor to unity. 53.9 kVAR adds the two tangents instead of subtracting them.

    Reference: Electrical theory (power-factor correction: kVAR = kW x (tan of the old angle - tan of the new angle)); no NEC section applies (NEC 2026)

  57. Electrical Services, Service Equipment, and Separately Derived Systems

    Three branch circuits protected at 20 A, 40 A and 70 A run in one raceway and share a single copper equipment grounding conductor. The sizing rows are: over 15 A through 20 A, 12 AWG; over 20 A through 60 A, 10 AWG; over 60 A through 100 A, 8 AWG; over 100 A through 200 A, 6 AWG. What is the minimum size of the shared equipment grounding conductor?

    1. 12 AWG
    2. 10 AWG
    3. 8 AWG
    4. 6 AWG
    Show answer

    Answer: 3. 8 AWG

    A shared equipment grounding conductor is sized for the largest overcurrent device in the raceway, which is 70 A; that falls in the over 60 A through 100 A row, so 8 AWG copper is required. 12 AWG is sized for the 20 A circuit, the smallest device. 10 AWG is sized for the 40 A circuit and skips the 70 A circuit. 6 AWG adds the device ratings, 130 A, and uses that row.

    Reference: NEC 250.122 (NEC 2026)

  58. Electrical Feeders

    Feeder conductors have an adjusted ampacity of 1,140 amperes and supply a switchboard. The next higher standard device rating is permitted only where the device is 800 amperes or less. Standard device ratings are 800, 1,000, 1,200 and 1,600 amperes. What is the largest overcurrent device permitted?

    1. 800 A
    2. 1,000 A
    3. 1,200 A
    4. 1,600 A
    Show answer

    Answer: 2. 1,000 A

    Above 800 amperes the next higher size is not permitted, so the device must be the largest standard rating not over 1,140 A, which is 1,000 A. 800 A confuses the 800 ampere limit of the next-size-up rule with the device rating. 1,200 A rounds up to the next standard size, which is not allowed above 800 A. 1,600 A rounds up two sizes.

    Reference: NEC 240.4 (overcurrent devices rated over 800 amperes) (NEC 2026)

  59. Branch Circuit Calculations and Conductors

    A workshop has 20 heavy-duty lampholders. For a load calculation outside a dwelling, each heavy-duty lampholder is counted at 600 VA. What lampholder load is added?

    1. 2,400 VA
    2. 3,600 VA
    3. 6,000 VA
    4. 12,000 VA
    Show answer

    Answer: 4. 12,000 VA

    20 lampholders at 600 VA each give 20 x 600 = 12,000 VA. 2,400 VA counts each lampholder at 120 VA. 3,600 VA counts each lampholder at 180 VA like a receptacle yoke. 6,000 VA counts each lampholder at 300 VA.

    Reference: NEC Article 120 (heavy-duty lampholder load) (NEC 2026)

  60. Electrical Wiring Methods and Electrical Materials

    Type NM cable runs 22 feet in a straight line between two boxes. The cable must be secured within 12 inches of each box and at intervals not exceeding 4-1/2 feet. What is the minimum number of securing points (staples)?

    1. 4
    2. 5
    3. 6
    4. 8
    Show answer

    Answer: 3. 6

    The first and last points can be 1 foot from the boxes, which leaves 20 feet between them, and 20 / 4.5 = 4.44 spaces, which rounds up to 5 spaces and 6 points. 4 rounds 4.89 down. 5 rounds the 4.44 spaces down, which leaves a gap longer than 4-1/2 feet. 8 adds an extra securing point at each box on top of the end points already within 12 in.

    Reference: NEC 334.30 (NEC 2026)

  61. Electrical Equipment and Devices

    A dwelling has 9,600 VA of electric heating and a 4,800 VA air-conditioning load, both at 240 volts. The two are interlocked so that they cannot operate at the same time. What current is entered for these two loads in the service calculation?

    1. 20.0 A
    2. 40.0 A
    3. 60.0 A
    4. 80.0 A
    Show answer

    Answer: 2. 40.0 A

    Only the larger of two noncoincident loads is counted, which is the 9,600 VA heating load, and 9,600 / 240 = 40.0 A. 20.0 A uses only the smaller air-conditioning load. 60.0 A adds both loads even though only one can run. 80.0 A divides the heating load by 120 volts.

    Reference: NEC Article 120 (noncoincident loads) (NEC 2026)

  62. Motors and Generators

    A 100-kW, 480Y/277-volt, three-phase generator is rated at a power factor of 0.8. The conductors from its output terminals to the first overcurrent device must have an ampacity of at least 115% of the nameplate current. The THHN copper conductors run where the ambient correction factor for the 90 degree C column is 0.82 (given), with three current-carrying conductors in the raceway, and all terminals are rated 75 degrees C. Copper ampacities (75 C / 90 C): 1/0 AWG 150 / 170 A; 2/0 AWG 175 / 195 A; 3/0 AWG 200 / 225 A; 4/0 AWG 230 / 260 A. What is the smallest conductor permitted?

    1. 1/0 AWG
    2. 2/0 AWG
    3. 3/0 AWG
    4. 4/0 AWG
    Show answer

    Answer: 3. 3/0 AWG

    The generator is 100 / 0.8 = 125 kVA, so its current is 125,000 / (1.732 x 480) = 150.4 A and the conductors need 150.36 x 1.15 = 172.9 A. 3/0 gives 225 x 0.82 = 184.5 A and 200 A at the terminals, while 2/0 corrects to only 159.9 A. 1/0 AWG finds the current from the kW rating instead of the kVA rating. 2/0 AWG skips the ambient correction. 4/0 AWG applies the correction factor to the 75 C column.

    Reference: NEC 445.13(A), 310.15(B) and 310.16 (NEC 2026)

  63. Renewable Energy Technologies

    A 400 W PV module has a power temperature coefficient of -0.35% per degree C. Its cells reach 65 degrees C, which is 40 degrees C above the 25 degree C test condition, while irradiance stays at the 1,000 W/m2 test value and the module operates at its maximum power point. Using only the temperature coefficient, what power does the module produce?

    1. 344.0 W
    2. 386.0 W
    3. 400.0 W
    4. 456.0 W
    Show answer

    Answer: 1. 344.0 W

    The power falls by 0.35% x 40 = 14%, so 400 x 0.86 = 344.0 W. 386.0 W subtracts 0.35 watt per degree instead of 0.35 percent. 400.0 W applies no temperature correction. 456.0 W raises the power instead of lowering it.

    Reference: Electrical theory (module power = rated power x (1 + temperature coefficient x temperature change)); no NEC section applies (NEC 2026)

  64. Calculations and Theory

    A 0.05-henry coil is connected to a 60-hertz supply. What is its inductive reactance, to the nearest 0.1 ohm?

    1. 1.9 ohms
    2. 3.0 ohms
    3. 9.4 ohms
    4. 18.8 ohms
    Show answer

    Answer: 4. 18.8 ohms

    XL = 2 x 3.1416 x 60 x 0.05 = 18.8496 ohms, or 18.8 ohms. 1.9 ohms misreads 0.05 henry as 0.005 henry. 3.0 ohms multiplies frequency by inductance only. 9.4 ohms leaves out the 2 in 2 x pi.

    Reference: Electrical theory (inductive reactance XL = 2 x pi x f x L); no NEC section applies (NEC 2026)

  65. Electrical Services, Service Equipment, and Separately Derived Systems

    A 208Y/120-volt, three-phase building has a 400-ampere service. A year of recorded demand data shows a maximum demand of 220 amperes. A 50 kVA, three-phase load will be added. For an existing building the existing load is taken as 125% of the measured maximum demand, and the new load is added at 100%. What is the calculated load in amperes?

    1. 138.8 A
    2. 275.0 A
    3. 358.8 A
    4. 413.8 A
    Show answer

    Answer: 4. 413.8 A

    The new load is 50,000 / (1.732 x 208) = 138.8 A, and the existing load is 1.25 x 220 = 275.0 A, so the calculated load is 413.8 A, which is above the 400 A service rating. 138.8 A counts only the new load. 275.0 A counts only the existing load at 125% and leaves out the new load. 358.8 A takes the measured maximum demand without the 125% factor.

    Reference: NEC Article 120 (existing loads determined from measured maximum demand) (NEC 2026)

  66. Electrical Feeders

    A feeder protected at 1,200 amperes runs as three parallel sets in three separate metal-free (PVC) raceways, each with its own wire-type copper equipment grounding conductor. The minimum phase conductors would be 600 kcmil per set, but 750 kcmil is installed to limit voltage drop. Copper EGC rows: not over 400 A, 3 AWG; not over 1,000 A, 2/0 AWG; not over 1,200 A, 3/0 AWG; not over 1,600 A, 4/0 AWG. Areas: 3 AWG 52.62 kcmil; 2 AWG 66.36 kcmil; 3/0 AWG 167.8 kcmil; 4/0 AWG 211.6 kcmil. What is the minimum EGC in each raceway?

    1. 3 AWG
    2. 2 AWG
    3. 3/0 AWG
    4. 4/0 AWG
    Show answer

    Answer: 4. 4/0 AWG

    Each parallel raceway needs a full-size EGC based on the 1,200 A device, which is 3/0 AWG (167.8 kcmil). Because the phase conductors were enlarged from 600 to 750 kcmil for voltage drop, the EGC grows by 750 / 600 = 1.25: 167.8 x 1.25 = 209.75 kcmil, so 4/0 AWG (211.6 kcmil) is required in each raceway. 3 AWG divides the 1,200 A device among the three raceways and does not increase the size. 2 AWG divides the device among the raceways and then applies the voltage-drop increase. 3/0 AWG uses the table size for 1,200 A but skips the increase for the larger phase conductors.

    Reference: NEC 250.122(A) and 250.122(D); Article 250 (equipment grounding conductors in parallel raceways) (NEC 2026)

  67. Electrical Wiring Methods and Electrical Materials

    A 90-degree conduit bend has a centerline radius of 14 inches. Using pi = 3.1416, what length of conduit does the bend itself use (the arc along the centerline)?

    1. 22.0 in
    2. 44.0 in
    3. 88.0 in
    4. 153.9 in
    Show answer

    Answer: 1. 22.0 in

    A 90-degree bend is a quarter of a circle, so the arc is 2 x 3.1416 x 14 / 4 = 21.99 inches, about 22.0 inches. 44.0 in uses a half circle. 88.0 in uses a full circle. 153.9 in uses the area of a quarter circle.

    Reference: Electrical theory (arc length of a 90-degree bend = pi x radius / 2); no NEC section applies (NEC 2026)

  68. Electrical Equipment and Devices

    A packaged air-conditioning unit has one hermetic motor-compressor with a rated-load current of 28.6 amperes and a condenser fan motor of 2.4 amperes. The conductors must carry 125% of the compressor current plus the fan current. The branch-circuit protective device is normally limited to 175% of the compressor current plus the fan current; because the unit will not start on that device, it may be increased to no more than 225% of the compressor current plus the fan current. If the result is not a standard rating, the next lower standard rating is used. Standard ratings: 40, 45, 50, 60, 70, 80 A. What are the minimum conductor ampacity and the maximum protective device rating?

    1. 31.0 A ampacity; 60 A device
    2. 38.2 A ampacity; 50 A device
    3. 38.2 A ampacity; 60 A device
    4. 38.2 A ampacity; 70 A device
    Show answer

    Answer: 3. 38.2 A ampacity; 60 A device

    The conductors need 1.25 x 28.6 + 2.4 = 38.15 A. The device may not exceed 2.25 x 28.6 + 2.4 = 66.75 A, and the next lower standard rating is 60 A. 31.0 A ampacity; 60 A device adds the compressor and fan currents without the 125% factor. 38.2 A ampacity; 50 A device stops at the normal 175% limit, although the unit will not start on that device. 38.2 A ampacity; 70 A device rounds the device up to the next higher standard rating.

    Reference: NEC 440.33 (conductors, motor-compressor with other loads), 440.22(A) and 440.22(B)(1) (branch-circuit short-circuit and ground-fault protective device, 225% maximum where 175% will not start the unit) and 240.6(A) (NEC 2026)

  69. Motors and Generators

    A 40-horsepower, 460-volt, three-phase motor (table full-load current 52 A) is supplied by tap conductors 20 feet long from a motor feeder whose conductors are 250 kcmil copper with an ampacity of 255 A. The feeder is protected by a 300-ampere device. For a motor feeder tap not over 25 feet, the tap conductors must have an ampacity of at least one-third of the ampacity of the feeder conductors, and never less than the motor branch-circuit conductors require. Copper ampacities at 75 degrees C: 6 AWG 65 A; 4 AWG 85 A; 3 AWG 100 A; 2 AWG 115 A. What is the smallest tap conductor?

    1. 6 AWG
    2. 4 AWG
    3. 3 AWG
    4. 2 AWG
    Show answer

    Answer: 2. 4 AWG

    The tap must carry at least 255 / 3 = 85.0 A, which is more than the motor's 1.25 x 52 = 65.0 A, so 85.0 A governs and 4 AWG (85 A) is the smallest conductor. 6 AWG checks only the motor branch-circuit requirement. 3 AWG takes one-third of the 300 A feeder device instead of one-third of the feeder conductor ampacity. 2 AWG adds the 125% motor factor on top of the one-third value.

    Reference: NEC 430.22 and Article 430 (motor feeder taps) (NEC 2026)

  70. Renewable Energy Technologies

    An electric vehicle battery needs 36 kWh added. The charger supplies 7.2 kW, and 90% of the energy it supplies reaches the battery. How many hours does the charge take?

    1. 4.5 h
    2. 5.0 h
    3. 5.6 h
    4. 6.2 h
    Show answer

    Answer: 3. 5.6 h

    Only 90% of the 7.2 kW reaches the battery, which is 6.48 kW, so the time is 36 / 6.48 = 5.56 hours. 4.5 h multiplies by the efficiency instead of dividing by it. 5.0 h ignores the charging losses. 6.2 h applies the 90% efficiency twice.

    Reference: Electrical theory (charging time = energy added to the battery / (charger power x efficiency)); no NEC section applies (NEC 2026)

Built by Tsai Electro. Its founder holds Taiwan's national Class B Indoor Wiring Technician certificate, has MEP site coordination experience on public projects, and teaches career switchers on YouTube (@tsai.electro). How we check questions · Refund policy · About Tsai Electro

How we check questions
  • Every question is original, written to the 2026 NEC for the Texas PSI two-part format, and checked in a separate review pass before it goes live.
  • Every answer that relies on the code names its NEC article and section, with an open-book lookup path, so you can confirm it in your own code book.
  • An outside reviewer verifies the set against the printed 2026 NEC in rounds. When a check finds a problem, the question is fixed or withdrawn, and the change is listed below with its date.
  • Every question names its source (the 2026 NEC section wherever one applies), is checked in a separate review pass, and every correction is published with its date.
  • Public correction log
  • Spot an error? Report it from the question. Reports are reviewed within 7 days.
Corrections log

The Texas Journeyman practice set has been on this site since 2026-09-30. After temporary quality withdrawals it contains 1,000 available questions and 10 complete two-part mocks.

  • Thirteen worked solutions now retain intermediate precision and distinguish rounded values from exact equalities; answers and code rules are unchanged. Three missing navigation paths were added from recorded NEC 2026 review references, with informative annexes labeled as such. No new questions or mock forms; this is not a new legal audit or professional signoff.
  • Question O50182: temporarily withdrawn while its source or explanation is verified; it is not served or scored.
  • Question O53134: temporarily withdrawn while its source or explanation is verified; it is not served or scored.
  • Question O55012: code reference changed from NEC 215.2(A)(1), 120.14(I) and Table 120.47; Article 120 (office receptacle load and noncoincident loads) to NEC 215.4(A)(1) (215.2(A)(1) in the 2023 NEC), 120.14(I), 120.43 and Table 120.47; Article 120 (office receptacle load and noncoincident loads). The answer did not change. Reason: citation now names 215.4(A)(1), where the feeder conductor sizing rule moved in the 2026 NEC, and adds 120.43 for the office receptacle minimum.
  • Question O55012: worked solution revised. The answer did not change. Reason: worked solution now cites 215.4(A)(1) and 120.43.
  • Question O55012: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 215.4(A)(1) instead of 215.2(A)(1) and adds 120.43.
  • Question O55013: code reference changed from NEC 215.2(A)(1), 310.15(B), 310.15(C)(1) and 310.16 to NEC 215.4(A)(1) and 215.4(A)(2) (215.2(A)(1) in the 2023 NEC), 310.15(B), 310.15(C)(1) and 310.16. The answer did not change. Reason: citation now names 215.4(A)(1) for the 125 percent terminal check and 215.4(A)(2) for the load after correction and adjustment, where the feeder rule moved in the 2026 NEC.
  • Question O55013: worked solution revised. The answer did not change. Reason: worked solution now cites 215.4(A)(1) and 215.4(A)(2).
  • Question O55013: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 215.4(A)(1) and 215.4(A)(2) instead of 215.2(A)(1).
  • Question O55015: code reference changed from NEC 215.2(A)(1), 430.24, 120.14(I) and Table 120.47 to NEC 215.4(A)(1) (215.2(A)(1) in the 2023 NEC), 430.24, 120.14(I) and Table 120.47. The answer did not change. Reason: citation now names 215.4(A)(1), where the feeder conductor sizing rule moved in the 2026 NEC.
  • Question O55015: worked solution revised. The answer did not change. Reason: worked solution now cites 215.4(A)(1).
  • Question O55015: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 215.4(A)(1) instead of 215.2(A)(1).
  • Question O55067: code reference changed from NEC 215.2(A)(1); Article 120 (feeder neutral load) to NEC 215.4(A)(1) (215.2(A)(1) in the 2023 NEC), Exception No. 3; Article 120 (feeder neutral load). The answer did not change. Reason: citation now names 215.4(A)(1) and its Exception No. 3, which lets a grounded conductor not connected to an overcurrent device be sized at 100 percent of the load.
  • Question O55067: worked solution revised. The answer did not change. Reason: worked solution now cites 215.4(A)(1) and its Exception No. 3.
  • Question O55067: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 215.4(A)(1) instead of 215.2(A)(1).
  • Question O54026: code reference changed from NEC 215.2(A)(1) and 110.14(C)(1)(b) to NEC 215.4(A)(1) (215.2(A)(1) in the 2023 NEC) and 110.14(C)(1)(b). The answer did not change. Reason: citation now names 215.4(A)(1), where the feeder conductor sizing rule moved in the 2026 NEC.
  • Question O54026: worked solution revised. The answer did not change. Reason: worked solution now cites 215.4(A)(1).
  • Question O54026: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 215.4(A)(1) instead of 215.2(A)(1).
  • Question O50428: code reference changed from NEC Article 310 (minimum size of conductors) to NEC 310.5(A). The answer did not change. Reason: citation now names 310.5(A), the 2026 general minimum conductor size rule.
  • Question O50428: question text revised. The answer did not change. Reason: stem now asks about aluminum conductors only, because 14 AWG is permitted for copper-clad aluminum under the 2026 general rule.
  • Question O50428: explanation revised. The answer did not change. Reason: explanation now gives the 2026 general minimums of 16 AWG copper, 14 AWG copper-clad aluminum and 12 AWG aluminum.
  • Question O50428: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 310.5(A) instead of the whole article.
  • Question O50442: code reference changed from NEC 310.15(B) to NEC 310.15(B)(2). The answer did not change. Reason: citation now names 310.15(B)(2), the rooftop temperature adder rule.
  • Question O50442: question text revised. The answer did not change. Reason: stem now uses the less than 3/4-inch rooftop threshold and THWN conductors, so the 33 degree C adder applies and the XHHW-2 exemption does not.
  • Question O50442: explanation revised. The answer did not change. Reason: explanation now states the less than 3/4-inch threshold and the XHHW-2 exemption.
  • Question O50442: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 310.15(B)(2) instead of 310.15(B).
  • Question O53107: code reference changed from NEC Table 430.52 to NEC Table 430.52(C)(1). The correct answer changed, but it is still option 2. Reason: citation now names Table 430.52(C)(1), the 2026 number of the motor short-circuit and ground-fault device table.
  • Question O53107: answer options revised. The correct answer changed, but it is still option 2. Reason: the keyed option now names Table 430.52(C)(1), the 2026 number of the same table.
  • Question O53107: explanation revised. The correct answer changed, but it is still option 2. Reason: explanation now names Table 430.52(C)(1).
  • Question O53107: open-book lookup path updated. The correct answer changed, but it is still option 2. Reason: lookup path now points to Table 430.52(C)(1) instead of Table 430.52.
  • Question O51263: code reference changed from NEC 700.12 to NEC 700.12(G)(2)(3). The answer did not change. Reason: citation now names 700.12(G)(2)(3), the 2026 branch-circuit rule for battery-equipped emergency luminaires.
  • Question O51263: question text revised. The answer did not change. Reason: stem now uses the 2026 term battery-equipped emergency luminaire and asks which connection is permitted, because the 2026 rule allows more than one arrangement.
  • Question O51263: explanation revised. The answer did not change. Reason: explanation now presents the same-circuit connection as one permitted arrangement and says why each other option is not one.
  • Question O51263: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 700.12(G)(2)(3) instead of 700.12.
  • Question O51198: code reference changed from NEC 705.12(B) to NEC 705.12(B)(2)(b). The answer did not change. Reason: citation now names 705.12(B)(2)(b), which requires the do-not-relocate warning for a power source output breaker.
  • Question O51198: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 705.12(B)(2)(b) instead of 705.12(B).
  • Question O52181: code reference changed from NEC 705.12(B) to NEC 705.12(B)(2)(a). The answer did not change. Reason: citation now names 705.12(B)(2)(a), the 120 percent busbar rule for a source breaker at the opposite end from the main.
  • Question O52181: worked solution revised. The answer did not change. Reason: worked solution now cites 705.12(B)(2)(a).
  • Question O52181: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 705.12(B)(2)(a) instead of 705.12(B).
  • Question O51262: code reference changed from NEC Article 800 (separation from power conductors) to NEC 722.133(B) (805.133(A)(2) in the 2023 NEC). The answer did not change. Reason: citation now names 722.133(B), where the in-building separation rule for communications cables moved in the 2026 NEC.
  • Question O51262: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 722.133(B) instead of Article 800.
  • Question O53122: code reference changed from NEC Article 800 (communications cable marking) to NEC 722.131(C) and Table 722.132. The answer did not change. Reason: citation now names 722.131(C) and Table 722.132, where communications cable types and plenum use are covered in the 2026 NEC.
  • Question O53122: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 722.131(C) and Table 722.132 instead of Article 800.
  • Question O51261: code reference changed from NEC Article 800 (communications primary protector) to NEC 742.10(A). The answer did not change. Reason: citation now names 742.10(A), where the primary protector rule moved in the 2026 NEC.
  • Question O51261: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 742.10(A) instead of Article 800.
  • Question O53070: code reference changed from NEC Article 342 (size of intermediate metal conduit) to NEC 342.20(B). The answer changed from option 2 to option 4. Reason: citation now names 342.20(B), which sets the largest trade size of IMC.
  • Question O53070: answer key changed. The answer changed from option 2 to option 4. Reason: the 2026 NEC permits IMC up to metric designator 155, trade size 6, so option 4 (6 inches) is the largest size permitted and option 2 (4 inches) is not.
  • Question O53070: explanation revised. The answer changed from option 2 to option 4. Reason: explanation now gives the 2026 limit of trade size 6 for IMC instead of trade size 4.
  • Question O53070: open-book lookup path updated. The answer changed from option 2 to option 4. Reason: lookup path now points to 342.20(B) instead of Article 342 alone.
  • Question O50140: code reference changed from NEC 250.24(B); Article 100 (Bonding Jumper, Main) to NEC 250.24(C) and 250.28; Article 100 (Bonding Jumper, Main). The answer did not change. Reason: citation now names 250.24(C), the 2026 location of the service main bonding jumper rule, and 250.28 for the jumper itself, instead of 250.24(B).
  • Question O50140: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 250.24(C) and 250.28 instead of 250.24(B).
  • Question O50164: code reference changed from NEC 300.4(A)(1) to NEC 300.6(A)(1) (300.4(A)(1) in the 2023 NEC). The answer did not change. Reason: citation now names 300.6(A)(1), where the bored-hole rule for wood framing moved in the 2026 NEC.
  • Question O50164: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 300.6(A)(1) instead of 300.4(A)(1).
  • Question O50230: code reference changed from NEC 300.20(A) to NEC 300.22(A) (300.20(A) in the 2023 NEC). The answer did not change. Reason: citation now names 300.22(A), where the rule on grouping conductors in ferrous raceways to avoid induction heating moved in the 2026 NEC.
  • Question O50230: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 300.22(A) instead of 300.20(A).
  • Question O51238: code reference changed from NEC 300.16(A) to NEC 300.16(B). The answer did not change. Reason: citation now names 300.16(B), the rule for box openings smaller than 8 in. in any dimension, instead of 300.16(A), the 6 in. general rule.
  • Question O51238: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 300.16(B) instead of 300.16(A).
  • Question O50473: code reference changed from NEC Article 404 (ratings and use of snap switches) to NEC 406.46(A)(4) (Article 404 in the 2023 NEC). The answer did not change. Reason: citation now names 406.46(A)(4), because the 2026 NEC moved general-use snap switches from Article 404 to Article 406.
  • Question O50473: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 406.46(A)(4) instead of Article 404.
  • Question O56006: code reference changed from NEC Article 404 (electronic lighting control switches) to NEC 406.50 and 406.2 (Article 404 in the 2023 NEC). The answer did not change. Reason: citation now names 406.50 for electronic control switches and 406.2 for listing, because the 2026 NEC moved these devices from Article 404 to Article 406.
  • Question O56006: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 406.50 and 406.2 instead of Article 404.
  • Question O50489: code reference changed from NEC Article 404 (switch connections) to NEC 406.30(A) (Article 404 in the 2023 NEC). The answer did not change. Reason: citation now names 406.30(A), because the 2026 NEC moved the wiring rule for three-way and four-way switches from Article 404 to Article 406.
  • Question O50489: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 406.30(A) instead of Article 404.
  • Question O53099: code reference changed from NEC Article 404 (dimmer switches) to NEC 406.46(D) (Article 404 in the 2023 NEC). The answer did not change. Reason: citation now names 406.46(D), because the 2026 NEC moved general-use dimmer switches from Article 404 to Article 406.
  • Question O53099: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 406.46(D) instead of Article 404.
  • Question O50632: code reference changed from NEC Article 404 (general-use snap switches controlling motors) to NEC 406.46(A)(4) (Article 404 in the 2023 NEC). The answer did not change. Reason: citation now names 406.46(A)(4), because the 2026 NEC moved the motor-load limit for general-use snap switches from Article 404 to Article 406.
  • Question O50632: worked solution revised. The answer did not change. Reason: worked solution now cites 406.46(A)(4).
  • Question O50632: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 406.46(A)(4) instead of Article 404.
  • Question O50022: code reference changed from NEC Article 450 (transformer secondary full-load current used with 450.3(B)) to NEC 450.5(B) and Table 450.5(B) (450.3(B) in the 2023 NEC; transformer secondary full-load current). The answer did not change. Reason: citation now names 450.5(B) and Table 450.5(B), where the transformer overcurrent protection rule moved in the 2026 NEC.
  • Question O50022: worked solution revised. The answer did not change. Reason: worked solution now cites 450.5(B) and Table 450.5(B).
  • Question O50022: open-book lookup path updated. The answer did not change. Reason: lookup path now points to Table 450.5(B) instead of 450.3(B).
  • Question O50073: code reference changed from NEC 450.3(B) to NEC 450.5(B) and Table 450.5(B) (450.3(B) in the 2023 NEC). The answer did not change. Reason: citation now names 450.5(B) and Table 450.5(B), where the transformer overcurrent protection rule moved in the 2026 NEC.
  • Question O50073: worked solution revised. The answer did not change. Reason: worked solution now cites 450.5(B) and Table 450.5(B).
  • Question O50073: open-book lookup path updated. The answer did not change. Reason: lookup path now points to Table 450.5(B) instead of 450.3(B).
  • Question O50121: code reference changed from NEC 450.3(B) (protection is sized from the secondary full-load current) to NEC 450.5(B) and Table 450.5(B) (protection is sized from the secondary full-load current; 450.3(B) in the 2023 NEC). The answer did not change. Reason: citation now names 450.5(B) and Table 450.5(B), where the transformer overcurrent protection rule moved in the 2026 NEC.
  • Question O50121: worked solution revised. The answer did not change. Reason: worked solution now cites 450.5(B) and Table 450.5(B).
  • Question O50121: open-book lookup path updated. The answer did not change. Reason: lookup path now points to Table 450.5(B) instead of 450.3(B).
  • Question O50142: code reference changed from NEC 590.6(A) to NEC 590.7(A)(1) (590.6(A) in the 2023 NEC). The answer did not change. Reason: citation now names 590.7(A)(1), where the 2026 NEC moved GFCI protection for temporary receptacles, because 590.6 now holds the general wiring rules.
  • Question O50142: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 590.7(A)(1) instead of 590.6(A).
  • Question O51196: code reference changed from NEC Article 820 (grounding of coaxial cable) to NEC 750.100(A)(3) (Article 820 in the 2023 NEC). The answer did not change. Reason: citation now names 750.100(A)(3), because the 2026 NEC moved coaxial cable shield bonding and grounding from Article 820 to Article 750.
  • Question O51196: explanation revised. The answer did not change. Reason: explanation now says the conductor needs an ampacity at least equal to that of the cable outer sheath and need not exceed 6 AWG, as the 2026 text states, instead of a capacity about equal to the shield.
  • Question O51196: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 750.100(A)(3) instead of Article 820.
  • Question O51046: code reference changed from NEC 250.52 to NEC 250.52(A)(5)(2). The answer did not change. Reason: citation now names 250.52(A)(5)(2), the diameter rule for rod electrodes.
  • Question O51046: explanation revised. The answer did not change. Reason: explanation drops the 1/2 in. minimum for listed rods, which the 2026 text does not state.
  • Question O51046: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 250.52(A)(5)(2) instead of 250.52.
  • Question O51329: code reference changed from NEC 250.119 to NEC 250.119(B). The answer did not change. Reason: citation now names 250.119(B), the identification rule for equipment grounding conductors 4 AWG and larger.
  • Question O51329: explanation revised. The answer did not change. Reason: explanation now says 4 AWG and larger, the 2026 size threshold, instead of larger than 6 AWG.
  • Question O51329: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 250.119(B) instead of 250.119.
  • Question O53065: code reference changed from NEC Article 300 (raceway seals for underground raceways entering buildings) to NEC 300.7(G). The correct answer changed, but it is still option 3. Reason: citation now names 300.7(G), the raceway seal rule.
  • Question O53065: question text revised. The correct answer changed, but it is still option 3. Reason: stem now states the 2026 condition that moisture could contact live parts and asks what the NEC requires, because the rule allows sealing at one or both ends.
  • Question O53065: answer options revised. The correct answer changed, but it is still option 3. Reason: the keyed option now requires sealing or plugging against moisture only, because the 2026 text mentions gas only in an informational note.
  • Question O53065: explanation revised. The correct answer changed, but it is still option 3. Reason: explanation now treats gas sealing as an informational note, not a requirement.
  • Question O53065: open-book lookup path updated. The correct answer changed, but it is still option 3. Reason: lookup path now points to 300.7(G) instead of Article 300.
  • Question O50472: code reference changed from NEC Article 404 (switches in damp or wet locations) to NEC 404.6(A). The answer did not change. Reason: citation now names 404.6(A), the rule for surface-mounted switches in damp or wet locations.
  • Question O50472: question text revised. The answer did not change. Reason: stem now says the switch is surface-mounted, because the weatherproof enclosure rule applies to surface-mounted switches and a flush-mounted switch takes a weatherproof cover.
  • Question O50472: explanation revised. The answer did not change. Reason: explanation now separates surface-mounted and flush-mounted switches and covers each wrong option.
  • Question O50472: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 404.6(A) instead of Article 404.
  • Question O56014: code reference changed from NEC Article 620 (feeder demand factors for elevators) to NEC 620.13(D), 620.14 and Table 620.14. The answer did not change. Reason: citation now names 620.13(D) for the sum of controller ratings and 620.14 with Table 620.14 for the elevator feeder demand factors.
  • Question O56014: worked solution revised. The answer did not change. Reason: worked solution now cites 620.13(D), 620.14 and Table 620.14.
  • Question O56014: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 620.13(D) and Table 620.14 instead of Article 620 alone.
  • Question O51265: code reference changed from NEC Article 670 (industrial machinery nameplate) to NEC 670.4(A)(2) (670.3 in the 2023 NEC). The answer did not change. Reason: citation now names 670.4(A)(2), where the industrial machinery nameplate rule moved in the 2026 NEC.
  • Question O51265: explanation revised. The answer did not change. Reason: explanation now adds the largest motor rating and the diagram number, as the 2026 nameplate list does.
  • Question O51265: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 670.4(A)(2) instead of Article 670.
  • Question O50638: code reference changed from NEC Article 670 (supply conductors for industrial machinery) to NEC 670.5(A) (670.4 in the 2023 NEC). The answer did not change. Reason: citation now names 670.5(A), where the supply conductor sizing rule for industrial machinery moved in the 2026 NEC.
  • Question O50638: worked solution revised. The answer did not change. Reason: worked solution now cites 670.5(A).
  • Question O50638: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 670.5(A) instead of Article 670.
  • Question O51228: code reference changed from NEC Article 210 (show windows) to NEC 210.62. The correct answer changed, but it is still option 3. Reason: citation now names 210.62, the show window receptacle rule.
  • Question O51228: question text revised. The correct answer changed, but it is still option 3. Reason: stem now asks how the receptacles must be placed, because the 2026 rule no longer counts them per 12 linear feet.
  • Question O51228: answer options revised. The correct answer changed, but it is still option 3. Reason: the keyed option now states the 2026 placement rule, and the older 12-foot counting rule replaces the 3-foot option as a distractor.
  • Question O51228: explanation revised. The correct answer changed, but it is still option 3. Reason: explanation now gives the 2026 rule of a receptacle within 18 inches of the top with no point along the top more than 6 feet away.
  • Question O51228: open-book lookup path updated. The correct answer changed, but it is still option 3. Reason: lookup path now points to 210.62 instead of the whole article.
  • Question O51096: question text revised. The answer did not change. Reason: stem now uses the 8 3/4 kW or more threshold of the exception instead of more than 8 3/4 kW.
  • Question O51093: code reference changed from NEC 210.52(E) to NEC 210.52(E)(3). The correct answer changed, but it is still option 2. Reason: citation now names 210.52(E)(3), the balcony, deck and porch receptacle rule.
  • Question O51093: question text revised. The correct answer changed, but it is still option 2. Reason: stem now places the deck within 4 inches horizontally of the dwelling unit, the 2026 condition, instead of accessible from inside.
  • Question O51093: answer options revised. The correct answer changed, but it is still option 2. Reason: the keyed option now says accessible from the deck and not more than 6 1/2 feet above its walking surface.
  • Question O51093: explanation revised. The correct answer changed, but it is still option 2. Reason: explanation now states the 2026 trigger and the height limit for the deck receptacle.
  • Question O51093: open-book lookup path updated. The correct answer changed, but it is still option 2. Reason: lookup path now points to 210.52(E)(3) instead of 210.52(E).
  • Question O51229: code reference changed from NEC Article 210 (electrical service areas) to NEC 210.63(B) (210.64 in the 2023 NEC). The answer did not change. Reason: citation now names 210.63(B), the 2026 location of the service equipment receptacle rule.
  • Question O51229: question text revised. The answer did not change. Reason: stem now states that the building wiring includes a solidly grounded system under 150 volts to ground, the 2026 condition for the rule.
  • Question O51229: explanation revised. The answer did not change. Reason: explanation now states the 2026 condition and the same room or area and 25-foot limits.
  • Question O51229: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 210.63(B) instead of the whole article.
  • Question O50189: code reference changed from NEC Article 625 (individual branch circuit for EV charging outlets) to NEC 625.40. The answer did not change. Reason: citation now names 625.40, the individual branch circuit rule for EVSE outlets.
  • Question O50189: question text revised. The answer did not change. Reason: stem now limits the outlet to EVSE rated more than 16 amperes with no power control system or adjustable settings, the conditions of the 2026 rule.
  • Question O50189: explanation revised. The answer did not change. Reason: explanation now gives the 16-ampere or 120-volt threshold and the exception for circuits shared under power control or adjustable settings.
  • Question O50189: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 625.40 instead of the whole article.
  • Question O51203: code reference changed from NEC Article 690 (overcurrent protection of PV source circuits) to NEC 690.9(A)(1). The correct answer changed, but it is still option 1. Reason: citation now names 690.9(A)(1), the 2026 test for PV circuit overcurrent protection.
  • Question O51203: question text revised. The correct answer changed, but it is still option 1. Reason: stem now asks for the Code test in a parallel-string system instead of a string count.
  • Question O51203: answer options revised. The correct answer changed, but it is still option 1. Reason: the keyed option now states the 690.9(A)(1) test, because the Code does not count strings.
  • Question O51203: explanation revised. The correct answer changed, but it is still option 1. Reason: explanation now gives the 690.9(A)(1) test and treats three strings in parallel as a common outcome, not the rule.
  • Question O51203: open-book lookup path updated. The correct answer changed, but it is still option 1. Reason: lookup path now points to 690.9(A)(1) instead of the whole article.
  • Question O50620: code reference changed from NEC Chapter 9, Table 1 (fill for one conductor) to NEC Chapter 9, Table 1 and Note (7). The answer did not change. Reason: citation now names Note (7) with Chapter 9, Table 1, because the stem now sets its single-cable allowance aside.
  • Question O50620: question text revised. The answer did not change. Reason: stem now asks for the 53% fill area and sets aside the Note (7) allowance, which could permit a larger single cable.
  • Question O50620: explanation revised. The answer did not change. Reason: explanation now names every wrong option and shows the larger cable the Note (7) allowance could permit.
  • Question O50620: worked solution revised. The answer did not change. Reason: worked solution now lists the Note (7) allowance as not applied.
  • Question O51089: code reference changed from NEC 210.52(C)(1) to NEC 210.52(C). The answer did not change. Reason: citation now names the 210.52(C) main paragraph, which sets the 12-inch width, instead of 210.52(C)(1).
  • Question O51089: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 210.52(C) instead of 210.52(C)(1).
  • Question O51095: code reference changed from NEC 210.70(A) to NEC 210.70(C). The correct answer changed, but it is still option 4. Reason: citation now names 210.70(C), the attic rule for all occupancies, instead of 210.70(A).
  • Question O51095: answer options revised. The correct answer changed, but it is still option 4. Reason: the keyed option now says the light is controlled at each point of entry to the attic, the 2026 rule, instead of at the usual point of entry.
  • Question O51095: explanation revised. The correct answer changed, but it is still option 4. Reason: explanation now gives the 2026 rule of a lighting outlet at or near the equipment with a point of control at each entry to the attic.
  • Question O51095: open-book lookup path updated. The correct answer changed, but it is still option 4. Reason: lookup path now points to 210.70(C) instead of 210.70(A).
  • Question O50043: code reference changed from NEC 200.6(A) to NEC 200.7(A) (200.6(A) in the 2023 NEC). The answer did not change. Reason: citation now names 200.7(A), where the identification rule for grounded conductors 6 AWG and smaller moved in the 2026 NEC.
  • Question O50043: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 200.7(A) instead of 200.6(A).
  • Question O50221: code reference changed from NEC 200.7(C)(1) to NEC 200.8(C)(1) (200.7(C)(1) in the 2023 NEC). The answer did not change. Reason: citation now names 200.8(C)(1), where the re-identification rule for white conductors in cable moved in the 2026 NEC.
  • Question O50221: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 200.8(C)(1) instead of 200.7(C)(1).
  • Question O51269: explanation revised. The answer did not change. Reason: explanation now uses the 2026 PV source circuit definition and no longer describes a PV output circuit running from the combiner to the inverter, a term the 2026 NEC no longer defines.
  • Question O51269: open-book lookup path updated. The answer did not change. Reason: lookup path now names the 2026 Article 100 entry PV dc Circuit, Source instead of PV Source Circuit.
  • Question O53009: code reference changed from NEC Article 90 (Code arrangement) to NEC 90.3. The correct answer changed, but it is still option 1. Reason: the 2026 NEC places the chapter arrangement rule in 90.3.
  • Question O53009: question text revised. The correct answer changed, but it is still option 1. Reason: stem now specifies the 2026 arrangement of the Code.
  • Question O53009: answer options revised. The correct answer changed, but it is still option 1. Reason: the keyed option now states the 2026 rule and the older wording is kept only as a distractor.
  • Question O53009: explanation revised. The correct answer changed, but it is still option 1. Reason: explanation now follows the 2026 rule that Chapters 5 through 8 supplement or modify Chapters 1 through 4.
  • Question O53009: open-book lookup path updated. The correct answer changed, but it is still option 1. Reason: lookup path now points to 90.3 instead of the whole article.
  • Question O51270: code reference changed from NEC Article 100 (PV Output Circuit) to NEC Article 100 (PV dc Circuit, Source). The correct answer changed, but it is still option 2. Reason: the 2026 NEC has no PV Output Circuit definition, so the citation now names the PV dc Circuit, Source definition.
  • Question O51270: question text revised. The correct answer changed, but it is still option 2. Reason: stem now asks for the 2026 term for dc conductors from a dc combiner to the inverter.
  • Question O51270: answer options revised. The correct answer changed, but it is still option 2. Reason: the keyed option is now PV source circuit and the removed term PV output circuit is kept only as a distractor.
  • Question O51270: explanation revised. The correct answer changed, but it is still option 2. Reason: explanation now follows the 2026 PV dc circuit definitions.
  • Question O51270: open-book lookup path updated. The correct answer changed, but it is still option 2. Reason: lookup path now points to the 2026 PV dc Circuit, Source definition.
  • Question O56011: code reference changed from NEC 110.16 (permanent label on service equipment rated 1,200 amperes or more) to NEC 110.16. The correct answer changed, but it is still option 4. Reason: citation no longer refers to a 1,200-ampere service label, which the 2026 110.16 does not have.
  • Question O56011: question text revised. The correct answer changed, but it is still option 4. Reason: stem no longer depends on the 1,200-ampere label and industry-practice alternative that the 2026 NEC removed.
  • Question O56011: answer options revised. The correct answer changed, but it is still option 4. Reason: the keyed option now lists the 2026 label content and the older 1,200-ampere label content is kept only as a distractor.
  • Question O56011: explanation revised. The correct answer changed, but it is still option 4. Reason: explanation now follows the 2026 110.16 marking content.
  • Question O52118: code reference changed from NEC 314.16(B) to NEC 314.16(B)(1), (B)(4) and (B)(5). The answer changed from option 3 to option 2. Reason: citation now names the 2026 grounding-conductor allowance rule in 314.16(B)(5) that decides this answer.
  • Question O52118: question text revised. The answer changed from option 3 to option 2. Reason: stem now calls the four conductors circuit conductors and states the 2026 rule that up to four equipment grounding conductors, isolated or not, share one allowance.
  • Question O52118: answer key changed. The answer changed from option 3 to option 2. Reason: under the 2026 rule the two grounding conductors count once, so the minimum volume is 15.75 cubic inches.
  • Question O52118: explanation revised. The answer changed from option 3 to option 2. Reason: explanation now counts both grounding conductors as one allowance and explains the old extra-allowance error.
  • Question O52118: worked solution revised. The answer changed from option 3 to option 2. Reason: worked solution now uses seven allowances and records 18.00 as the old isolated-allowance error.
  • Question O56008: code reference changed from NEC Article 406 (dimmer-controlled receptacles) to NEC 406.46(D). The correct answer changed, but it is still option 4. Reason: the 2026 Article 406 no longer has the dimmer-controlled receptacle rule, so the citation now points to the general-use dimmer rule in 406.46(D).
  • Question O56008: question text revised. The correct answer changed, but it is still option 4. Reason: stem now asks when a general-use dimmer may control receptacle-supplied lamps under the 2026 rule.
  • Question O56008: answer options revised. The correct answer changed, but it is still option 4. Reason: the keyed option now states the 2026 dimmer listing condition instead of the removed nonstandard plug and receptacle rule.
  • Question O56008: explanation revised. The correct answer changed, but it is still option 4. Reason: explanation now follows the 2026 406.46(D) rule for general-use dimmer switches.
  • Question O56008: open-book lookup path updated. The correct answer changed, but it is still option 4. Reason: lookup path now points to 406.46(D) instead of the whole article.
  • Question O56005: code reference changed from NEC Article 424 (color identification of heating cable nonheating leads) to NEC 424.35. The correct answer changed, but it is still option 2. Reason: the 2026 NEC no longer has the nonheating lead color code, so the citation now points to the 424.35 marking rule.
  • Question O56005: question text revised. The correct answer changed, but it is still option 2. Reason: stem now asks for the 2026 heating cable marking instead of the removed lead color code.
  • Question O56005: answer options revised. The correct answer changed, but it is still option 2. Reason: the keyed option now lists the 2026 marking content and the old lead color code is kept only as a distractor.
  • Question O56005: explanation revised. The correct answer changed, but it is still option 2. Reason: explanation now follows the 2026 424.35 marking content.
  • Question O56005: open-book lookup path updated. The correct answer changed, but it is still option 2. Reason: lookup path now points to 424.35 instead of the whole article.
  • Question O56013: code reference changed from NEC Article 100 (Within Sight) to NEC 110.29 (Article 100 definition in the 2023 NEC). The answer did not change. Reason: the 2026 NEC places the within-sight rule in 110.29 instead of an Article 100 definition.
  • Question O56013: worked solution revised. The answer did not change. Reason: worked solution now cites 110.29.
  • Question O56013: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 110.29 instead of the Article 100 definition.
  • Question O50168: code reference changed from NEC 406.12 to NEC 406.26(1) (406.12 in the 2023 NEC). The answer did not change. Reason: tamper-resistant receptacle locations moved from 406.12 to 406.26 in the 2026 NEC.
  • Question O50168: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 406.26, the 2026 location of the tamper-resistant rule.
  • Question O50242: code reference changed from NEC 406.5(E) to NEC 406.14(G)(1) (406.5 in the 2023 NEC). The answer did not change. Reason: the face-up countertop receptacle rule moved from 406.5 to 406.14(G)(1) in the 2026 NEC.
  • Question O50242: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 406.14(G)(1), the 2026 location of the rule.
  • Question O51352: code reference changed from NEC Article 100 (Closet Storage Space) to NEC 410.16(A). The answer did not change. Reason: the 2026 NEC gives the closet storage space dimensions in 410.16(A); Article 100 only defines the term.
  • Question O51352: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 410.16(A), where the 2026 dimensions are.
  • Question O50619: code reference changed from NEC 314.16(B) to NEC 314.16(B)(1), (B)(4) and (B)(5). The answer did not change. Reason: citation now names the 2026 conductor, device and grounding-conductor allowance rules.
  • Question O50619: question text revised. The answer did not change. Reason: stem now states that only two equipment grounding conductors enter, so the single allowance applies.
  • Question O50619: explanation revised. The answer did not change. Reason: explanation now says why the grounding conductors count as one allowance.
  • Question O50619: worked solution revised. The answer did not change. Reason: worked solution now records the number of grounding conductors and the 2026 citation.
  • Question O54047: code reference changed from NEC 314.16(B) to NEC 314.16(B)(1), (B)(4) and (B)(5). The answer did not change. Reason: citation now names the 2026 conductor, device and grounding-conductor allowance rules.
  • Question O54047: question text revised. The answer did not change. Reason: stem now states that no more than four equipment grounding conductors will enter the box, so they count as one allowance.
  • Question O54047: explanation revised. The answer did not change. Reason: explanation now says why the grounding conductors count as one allowance and correctly describes the 4-conductor distractor as also leaving out the grounding allowance.
  • Question O54047: worked solution revised. The answer did not change. Reason: worked solution now records the grounding conductor count, the 2026 citation and the corrected 4-conductor distractor description.
  • Question O54009: code reference changed from NEC Article 120 (electric vehicle supply equipment load in a service calculation) to NEC 120.57 (electric vehicle supply equipment load). The correct answer changed, but it is still option 2. Reason: citation now names 120.57, the 2026 rule for the EVSE load.
  • Question O54009: question text revised. The correct answer changed, but it is still option 2. Reason: stem now states the 2026 rule that EVSE counts at nameplate where available and 7,200 W only where no nameplate rating is available, and gives as a condition that no demand factor or multiplier applies.
  • Question O54009: answer options revised. The correct answer changed, but it is still option 2. Reason: options are rebuilt from the 2026 result of 164.0 A, and 170.0 A is kept as the older larger-of rule distractor.
  • Question O54009: explanation revised. The correct answer changed, but it is still option 2. Reason: explanation now uses the nameplate ratings and explains the older larger-of rule as an error.
  • Question O54009: worked solution revised. The correct answer changed, but it is still option 2. Reason: worked solution now counts each unit at its nameplate rating.
  • Question O54009: open-book lookup path updated. The correct answer changed, but it is still option 2. Reason: lookup path now points to 120.57 instead of the whole article.
  • Question O55007: code reference changed from NEC Article 120 (optional calculation for a one-family dwelling; 220.82 in the 2023 NEC) to NEC 120.82(B) and 120.82(C)(3) (220.82 in the 2023 NEC). The correct answer changed, but it is still option 2. Reason: citation now names 120.82(B) and 120.82(C)(3), the 2026 optional-method rules this item uses.
  • Question O55007: question text revised. The correct answer changed, but it is still option 2. Reason: stem now gives the 2026 first step of 8,000 VA at 100% instead of the 2023 first 10,000 VA.
  • Question O55007: answer options revised. The correct answer changed, but it is still option 2. Reason: options are recomputed from the 2026 first step of 8,000 VA, keeping the same three error types.
  • Question O55007: explanation revised. The correct answer changed, but it is still option 2. Reason: explanation now works the calculation with the 2026 first step of 8,000 VA.
  • Question O55007: worked solution revised. The correct answer changed, but it is still option 2. Reason: worked solution now uses the 2026 first step of 8,000 VA.
  • Question O55007: open-book lookup path updated. The correct answer changed, but it is still option 2. Reason: lookup path now points to 120.82(B) and 120.82(C)(3) instead of the whole article.
  • Question O55008: code reference changed from NEC Article 120 (optional calculation for an existing dwelling unit; 220.83 in the 2023 NEC) to NEC 120.83 and Table 120.83 (220.83 in the 2023 NEC). The correct answer changed, but it is still option 4. Reason: citation now names 120.83 and Table 120.83, the 2026 method for an existing dwelling.
  • Question O55008: question text revised. The correct answer changed, but it is still option 4. Reason: stem now gives the Table 120.83 percentages and says the first 8,000 VA comes from the existing load.
  • Question O55008: answer options revised. The correct answer changed, but it is still option 4. Reason: options are recomputed with the new air conditioner at 50% under Table 120.83, keeping the same three error types.
  • Question O55008: explanation revised. The correct answer changed, but it is still option 4. Reason: explanation now applies Table 120.83, with the new air conditioner at 50%.
  • Question O55008: worked solution revised. The correct answer changed, but it is still option 4. Reason: worked solution now applies the Table 120.83 percentages.
  • Question O55008: open-book lookup path updated. The correct answer changed, but it is still option 4. Reason: lookup path now points to 120.83 and Table 120.83 instead of the whole article.
  • Question O55059: code reference changed from NEC Article 120 (optional calculation for a one-family dwelling; 220.82 in the 2023 NEC) to NEC 120.82(B) and 120.82(C)(4) (220.82 in the 2023 NEC). The correct answer changed, but it is still option 4. Reason: citation now names 120.82(B) and 120.82(C)(4), the 2026 optional-method rules this item uses.
  • Question O55059: question text revised. The correct answer changed, but it is still option 4. Reason: stem now gives the 2026 first step of 8,000 VA at 100% instead of the 2023 first 10,000 VA.
  • Question O55059: answer options revised. The correct answer changed, but it is still option 4. Reason: options are recomputed from the 2026 first step of 8,000 VA, keeping the same three error types.
  • Question O55059: explanation revised. The correct answer changed, but it is still option 4. Reason: explanation now works the calculation with the 2026 first step of 8,000 VA.
  • Question O55059: worked solution revised. The correct answer changed, but it is still option 4. Reason: worked solution now uses the 2026 first step of 8,000 VA.
  • Question O55059: open-book lookup path updated. The correct answer changed, but it is still option 4. Reason: lookup path now points to 120.82(B) and 120.82(C)(4) instead of the whole article.
  • Question O52039: code reference changed from NEC Article 120 (optional calculation for a one-family dwelling) to NEC 120.82(B) and 120.82(C)(1) (220.82 in the 2023 NEC). The correct answer changed, but it is still option 4. Reason: citation now names 120.82(B) and 120.82(C)(1), the 2026 optional-method rules this item uses.
  • Question O52039: question text revised. The correct answer changed, but it is still option 4. Reason: stem now gives the 2026 first step of 8,000 VA at 100% instead of the 2023 first 10,000 VA.
  • Question O52039: answer options revised. The correct answer changed, but it is still option 4. Reason: options are recomputed from the 2026 first step of 8,000 VA, keeping the same three error types.
  • Question O52039: explanation revised. The correct answer changed, but it is still option 4. Reason: explanation now works the calculation with the 2026 first step of 8,000 VA.
  • Question O52039: worked solution revised. The correct answer changed, but it is still option 4. Reason: worked solution now uses the 2026 first step of 8,000 VA.
  • Question O52039: open-book lookup path updated. The correct answer changed, but it is still option 4. Reason: lookup path now points to 120.82(B) and 120.82(C)(1) instead of the whole article.
  • Question O55071: code reference changed from NEC Article 120 (optional calculation for an existing dwelling unit; 220.83 in the 2023 NEC) to NEC 120.83 and Table 120.83 (220.83 in the 2023 NEC). The correct answer changed, but it is still option 1. Reason: citation now names 120.83 and Table 120.83, the 2026 method for an existing dwelling.
  • Question O55071: question text revised. The correct answer changed, but it is still option 1. Reason: stem now gives the Table 120.83 percentages, including 80% for new EVSE, and says the first 8,000 VA comes from the existing load.
  • Question O55071: answer options revised. The correct answer changed, but it is still option 1. Reason: options are recomputed with the new EVSE at 80% under Table 120.83, keeping the original error types.
  • Question O55071: explanation revised. The correct answer changed, but it is still option 1. Reason: explanation now applies Table 120.83, with the new EVSE at 80%.
  • Question O55071: worked solution revised. The correct answer changed, but it is still option 1. Reason: worked solution now applies the Table 120.83 percentages.
  • Question O55071: open-book lookup path updated. The correct answer changed, but it is still option 1. Reason: lookup path now points to 120.83 and Table 120.83 instead of the whole article.
  • Question O56004: answer options revised. The correct answer changed, but it is still option 2. Reason: the keyed option now states the 2026 permission for a cord identified as suitable in the manufacturer's installation instructions.
  • Question O56004: explanation revised. The correct answer changed, but it is still option 2. Reason: explanation now follows the 2026 wording of 422.16(B)(3) and drops the servicing-only limit.
  • Question O56001: code reference changed from NEC Article 440 (equipment grounding conductor for rooftop equipment supplied through nonthreaded fittings) to NEC 440.9. The answer did not change. Reason: citation now names 440.9, the 2026 rooftop grounding rule.
  • Question O56001: question text revised. The answer did not change. Reason: stem now specifies compression-type fittings, the 2026 trigger, instead of set-screw fittings and the multimotor qualifier.
  • Question O56001: explanation revised. The answer did not change. Reason: explanation now follows the 2026 compression-fitting trigger in 440.9.
  • Question O56001: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 440.9 instead of the whole article.
  • Question O51224: code reference changed from NEC Article 517 (selectivity of ground-fault protection in hospitals) to NEC 517.17(C). The correct answer changed, but it is still option 4. Reason: citation now names 517.17(C), the 2026 selectivity rule.
  • Question O51224: question text revised. The correct answer changed, but it is still option 4. Reason: stem now asks what governs the separation instead of asking for a minimum time that the 2026 rule no longer sets.
  • Question O51224: answer options revised. The correct answer changed, but it is still option 4. Reason: the keyed option now states the 2026 selectivity requirement and the old six-cycle value is kept only as a distractor.
  • Question O51224: explanation revised. The correct answer changed, but it is still option 4. Reason: explanation now follows the 2026 selectivity requirement instead of a fixed six-cycle separation.
  • Question O51224: open-book lookup path updated. The correct answer changed, but it is still option 4. Reason: lookup path now points to 517.17(C) instead of the whole article.
  • Question O51212: code reference changed from NEC 230.70(A) to NEC 230.70(A)(2) and 230.70(A)(3). The answer did not change. Reason: citation now names 230.70(A)(2) for multifamily dwellings and 230.70(A)(3) for the bathroom prohibition.
  • Question O51212: question text revised. The answer did not change. Reason: stem now names a multifamily dwelling so the 2026 outdoor rule for one- and two-family dwellings does not apply.
  • Question O51212: answer options revised. The answer did not change. Reason: the garage option now says it is nearest the point of entrance so it is clearly a permitted location.
  • Question O51212: explanation revised. The answer did not change. Reason: explanation now separates the multifamily rule from the 2026 one- and two-family outdoor rule.
  • Question O51212: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 230.70(A)(2) and 230.70(A)(3).
  • Question O51153: code reference changed from NEC Article 410 (installation of luminaires on fiberboard) to NEC 410.136(B). The answer did not change. Reason: citation now names 410.136(B), the 2026 fiberboard rule.
  • Question O51153: question text revised. The answer did not change. Reason: stem now says the luminaire contains an LED driver, which is what brings it under the 2026 fiberboard rule.
  • Question O51153: explanation revised. The answer did not change. Reason: explanation now states that the rule covers luminaires containing a ballast, transformer, LED driver or power supply.
  • Question O51153: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 410.136(B) instead of the whole article.
  • Question O51245: code reference changed from NEC Article 410 (poles supporting luminaires) to NEC 410.30(B)(1). The answer did not change. Reason: citation now names 410.30(B)(1), the 2026 pole handhole rule.
  • Question O51245: question text revised. The answer did not change. Reason: stem now gives a 25-ft pole without a hinged base so the hinged-base exception cannot apply.
  • Question O51245: explanation revised. The answer did not change. Reason: explanation now says why the hinged-base exception does not apply to this pole.
  • Question O51245: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 410.30(B)(1) instead of the whole article.
  • Question O50479: code reference changed from NEC Article 410 (grounding of luminaires) to NEC 410.42. The correct answer changed, but it is still option 4. Reason: citation now names 410.42, the 2026 rule for exposed conductive parts.
  • Question O50479: question text revised. The correct answer changed, but it is still option 4. Reason: stem now asks for the general rule so the narrow exceptions do not make another option correct.
  • Question O50479: answer options revised. The correct answer changed, but it is still option 4. Reason: the keyed option now drops the pre-2026 "or insulated from ground" alternative.
  • Question O50479: explanation revised. The correct answer changed, but it is still option 4. Reason: explanation now follows the 2026 rule and names its narrow exceptions.
  • Question O50479: open-book lookup path updated. The correct answer changed, but it is still option 4. Reason: lookup path now points to 410.42 instead of the whole article.
  • Question O51148: code reference changed from NEC Article 422 (appliance disconnecting means) to NEC 422.31(A). The answer did not change. Reason: citation now names 422.31(A), the 2026 rule for small permanently connected appliances.
  • Question O51148: question text revised. The answer did not change. Reason: stem now says the branch-circuit breaker is within sight from the appliance, the condition 422.31(A) requires.
  • Question O51148: explanation revised. The answer did not change. Reason: explanation now includes the within-sight or lockable condition.
  • Question O51148: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 422.31(A) instead of the whole article.
  • Question O50482: code reference changed from NEC Article 422 (GFCI protection of appliances) to NEC 422.5(A)(3). The answer did not change. Reason: citation now names 422.5(A)(3), the 2026 GFCI rule for high-pressure spray washers.
  • Question O50482: answer options revised. The answer did not change. Reason: the keyed option now says the washer is cord-and-plug connected and 120 volts, matching 422.5(A)(3).
  • Question O50482: explanation revised. The answer did not change. Reason: explanation now states the cord-and-plug and voltage and current limits of the 2026 rule.
  • Question O50482: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 422.5(A)(3) instead of the whole article.
  • Question O54083: code reference changed from NEC Article 630 (arc welders, overcurrent protection) to NEC 630.12(A). The answer did not change. Reason: citation now names 630.12(A), the 2026 welder overcurrent rule.
  • Question O54083: question text revised. The answer did not change. Reason: stem now says the nameplate does not give I1max, which is when 200% of the rated primary current applies.
  • Question O54083: explanation revised. The answer did not change. Reason: explanation now says why the rated primary current is used.
  • Question O54083: worked solution revised. The answer did not change. Reason: worked solution now records that I1max is not given.
  • Question O54083: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 630.12(A) instead of the whole article.
  • Question O55041: code reference changed from NEC Article 695 (fire pump supply overcurrent device and conductor ampacity) to NEC 695.5(B)(2)(a)(1) and 695.7(B)(1). The answer did not change. Reason: citation now names 695.5(B)(2)(a)(1) and 695.7(B)(1), the 2026 device and conductor rules.
  • Question O55041: question text revised. The answer did not change. Reason: stem now gives the 2026 device rule of the largest fire pump locked-rotor current plus the other pump full-load current and accessories.
  • Question O55041: explanation revised. The answer did not change. Reason: explanation now computes the device sum as 370.4 A under the 2026 rule; the 400 A answer is unchanged.
  • Question O55041: worked solution revised. The answer did not change. Reason: worked solution now uses the 2026 device sum of 370.4 A.
  • Question O55041: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 695.5(B)(2)(a)(1) and 695.7(B)(1) instead of the whole article.
  • Question O50625: code reference changed from NEC Article 440 (branch-circuit short-circuit and ground-fault protection) to NEC 440.22(A) and Exception No. 1. The answer changed from option 3 to option 2. Reason: citation now names 440.22(A) and its Exception No. 1, which sets the maximum.
  • Question O50625: question text revised. The answer changed from option 3 to option 2. Reason: stem now states the 2026 permission to go up to the next higher standard size instead of the next lower size.
  • Question O50625: answer key changed. The answer changed from option 3 to option 2. Reason: under 440.22(A) Exception No. 1 the maximum is the next higher standard size above 32.55 A, which is 35 A.
  • Question O50625: explanation revised. The answer changed from option 3 to option 2. Reason: explanation now rounds up to 35 A under Exception No. 1.
  • Question O50625: worked solution revised. The answer changed from option 3 to option 2. Reason: worked solution now rounds up to the next higher standard size, 35 A.
  • Question O50625: open-book lookup path updated. The answer changed from option 3 to option 2. Reason: lookup path now points to 440.22(A) instead of the whole article.
  • Question O55056: code reference changed from NEC 440.32, 310.15(B) and 310.16; Article 310 (temperature adder for raceways on rooftops) to NEC 440.35, 310.15(B)(2), Table 310.15(B)(1)(1), Table 310.16 and 110.14(C). The answer did not change. Reason: a marked minimum circuit ampacity falls under 440.35, not 440.32, and the rooftop adder is in 310.15(B)(2).
  • Question O55056: question text revised. The answer did not change. Reason: stem now gives the 2026 rooftop adder threshold of less than 3/4 inch instead of 7/8 inch; the raceway still lies on the roof.
  • Question O55056: worked solution revised. The answer did not change. Reason: worked solution now cites 440.35 and the 2026 rooftop adder location.
  • Question O55056: open-book lookup path updated. The answer did not change. Reason: lookup path now points to 440.35 and 310.15(B)(2) instead of 440.32 and 310.15(B).
  • Question O50448: code reference changed from NEC Article 210 (receptacle near electrical service equipment) to NEC 210.63(B). The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50448: question text revised. The answer did not change. Reason: stem now states the occupancy and system-voltage conditions the code requires.
  • Question O50448: explanation revised. The answer did not change. Reason: explanation now matches the conditions of the rule and drops an unverified claim about an older distance.
  • Question O56020: code reference changed from NEC 551.71(A) to NEC 551.71(A)(2), 551.71(A)(3) and 551.71(B). The answer did not change. Reason: citation now names the 2026 NEC new-site percentage, the overlap rule and the tent-site exclusion.
  • Question O56020: question text revised. The answer did not change. Reason: stem now states that no site is a dedicated tent site and that every 50-ampere site also has a 30-ampere receptacle.
  • Question O56020: explanation revised. The answer did not change. Reason: explanation now explains the overlap between the 50-ampere and 30-ampere site groups.
  • Question O56020: worked solution revised. The answer did not change. Reason: solution now gives the code reason the 70 percent applies to all 47 sites.
  • Question O56018: code reference changed from NEC 120.140(B)(2)-(4) (550.18(B) in the 2023 NEC) to NEC 120.140(A)(5) and 120.140(B)(1)-(4) (550.18 in the 2023 NEC). The answer did not change. Reason: citation now names every 2026 NEC subsection the calculation uses.
  • Question O50323: question text revised. The answer did not change. Reason: stem now states the per-lot basis the 2026 NEC uses, the larger of 16,000 VA or the largest home accepted.
  • Question O50323: explanation revised. The answer did not change. Reason: explanation now explains why 16,000 VA is the per-lot value and why each wrong option is wrong.
  • Question O50323: worked solution revised. The answer did not change. Reason: solution now cites the 2026 NEC location and the per-lot basis.
  • Question O55069: code reference changed from NEC Article 550 (mobile home park feeder and service demand) to NEC 120.141 and Table 120.141 (Article 550 in the 2023 NEC). The answer did not change. Reason: the park load calculation is in 120.141 in the 2026 NEC, not Article 550.
  • Question O53048: code reference changed from NEC Article 215 to NEC 215.1 and its Informational Note. The answer did not change. Reason: citation now points to the scope section that sets the voltage limit.
  • Question O53048: question text revised. The answer did not change. Reason: stem now states the voltage limit of the article's scope.
  • Question O53048: explanation revised. The answer did not change. Reason: explanation now states the voltage limit and where higher-voltage feeders are covered.
  • Question O50122: code reference changed from NEC 210.19 (branch-circuit conductors for continuous loads) to NEC 210.19(A)(1). The answer did not change. Reason: citation now points to the specific 2026 NEC subsection instead of the whole section.
  • Question O50122: question text revised. The answer did not change. Reason: stem now states the condition the code requires by ruling out the 100%-rated assembly and other exceptions.
  • Question O50122: explanation revised. The answer did not change. Reason: explanation now says why 16 A is wrong under the stated conditions.
  • Question O50122: worked solution revised. The answer did not change. Reason: solution now cites 210.19(A)(1) and the excluded exceptions.
  • Question O51083: code reference changed from NEC Article 210 (branch-circuit ratings) to NEC 210.18. The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O51083: question text revised. The answer did not change. Reason: stem now limits the question to branch circuits other than individual branch circuits, which is what the standard-rating list covers.
  • Question O51083: explanation revised. The answer did not change. Reason: explanation now lists the 2026 standard ratings, including the restricted 10-ampere rating, and no longer claims that ratings above 50 amperes are permitted only for individual branch circuits.
  • Question O50438: code reference changed from NEC Article 210 (branch-circuit rating) to NEC 210.18. The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50439: code reference changed from NEC Article 210 (branch-circuit voltage limitations) to NEC 210.6(A). The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50439: question text revised. The answer did not change. Reason: stem now excludes the listed exceptions so the general limit is the only answer.
  • Question O50439: explanation revised. The answer did not change. Reason: explanation now notes the exceptions and why each wrong option is wrong.
  • Question O50436: code reference changed from NEC Article 210 (multiple branch circuits on the same yoke) to NEC 210.7. The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50449: code reference changed from NEC Article 210 (GFCI protection for specific appliances) to NEC 210.8(D)(7). The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50449: question text revised. The answer did not change. Reason: stem now matches the 2026 rule, which covers the branch circuit or outlet supplying the appliance.
  • Question O50449: explanation revised. The answer did not change. Reason: explanation now uses the same branch-circuit-or-outlet wording as the 2026 rule.
  • Question O50218: question text revised. The answer did not change. Reason: stem now excludes the motor and arc-welder exceptions so 20 amperes is the only minimum.
  • Question O50218: explanation revised. The answer did not change. Reason: explanation now names the two exceptions the stem excludes.
  • Question O51096: code reference changed from NEC 210.19 to NEC 210.19(C), Exception No. 2; Table 120.55, Column C. The answer did not change. Reason: citation now points to the 2026 neutral exception and the table column it depends on.
  • Question O51096: question text revised. The answer did not change. Reason: stem now states the 3-wire circuit, range rating and Column C demand conditions the neutral exception requires.
  • Question O51096: explanation revised. The answer did not change. Reason: explanation now ties the 70 percent neutral to the exception's conditions instead of teaching it as a blanket rule.
  • Question O51097: code reference changed from NEC 210.19 to NEC 210.19(C). The answer did not change. Reason: citation now points to the specific 2026 NEC subsection instead of the whole section.
  • Question O51097: explanation revised. The answer did not change. Reason: explanation now makes clear that 40 amperes is a minimum, not a size that is always enough.
  • Question O51226: code reference changed from NEC Article 210 (lampholders) to NEC 210.21(A). The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O51226: explanation revised. The answer did not change. Reason: explanation now states the 20-ampere threshold and drops lampholder wattage figures that were not checked against the 2026 text.
  • Question O50616: code reference changed from NEC Article 210 (continuous loads on branch circuits) to NEC 210.20(A). The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50616: question text revised. The answer did not change. Reason: stem now rules out the 100%-rated assembly exception that would change the 80 percent limit.
  • Question O50616: explanation revised. The answer did not change. Reason: explanation now gives the reason for each wrong option.
  • Question O54034: code reference changed from NEC Article 210 (branch circuit loading for continuous loads) to NEC 210.20(A). The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50199: code reference changed from NEC Table 120.130(A) (Table 551.73(A) in the 2023 NEC) to NEC 120.130(A)(2), 120.130(B) and Table 120.130(A) (551.73(A) in the 2023 NEC). The answer did not change. Reason: citation now names the 2026 NEC subsections the calculation uses, not only the demand table.
  • Question O50199: question text revised. The answer did not change. Reason: stem now limits the calculation to one feeder that serves only 20/30-ampere sites, so the park can still meet the 50-ampere site percentage.
  • Question O50199: explanation revised. The answer did not change. Reason: explanation now says where the park's 50-ampere sites are and names the 41 percent factor from the 2026 table.
  • Question O50199: worked solution revised. The answer did not change. Reason: solution givens now match the one-feeder stem.
  • Question O51309: code reference changed from NEC Article 551 (RV site supply equipment) to NEC 551.77(D). The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O51309: question text revised. The answer did not change. Reason: stem now asks about site supply equipment above the electrical datum plane, which is what the code measures.
  • Question O51309: explanation revised. The answer did not change. Reason: explanation now states the code's height range and drops the water-and-snow rationale that is not code text.
  • Question O50006: code reference changed from NEC 215.12(C)(1) to NEC 215.12(C)(2)(a)-(b). The answer did not change. Reason: this two-voltage-system question is governed by 215.12(C)(2), not the one-voltage-system rule in 215.12(C)(1).
  • Question O50006: answer option wording revised. The answer did not change. Reason: keyed option now makes clear that readily available documentation is an alternative to posting at each panelboard.
  • Question O50023: code reference changed from NEC 215.2(A)(1) to NEC 215.4(A)(1) (215.2(A)(1) in the 2023 NEC). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50023: question text revised. The answer did not change. Reason: stem now states the general-rule condition by ruling out the 100%-rated assembly and other exceptions.
  • Question O50023: explanation revised. The answer did not change. Reason: explanation now covers every wrong option under the stated conditions.
  • Question O50023: worked solution revised. The answer did not change. Reason: solution now cites 215.4(A)(1) and the excluded exceptions.
  • Question O50074: code reference changed from NEC 215.3 to NEC 215.5 (215.3 in the 2023 NEC). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50143: code reference changed from NEC 215.3 to NEC 215.5 (215.3 in the 2023 NEC). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50426: code reference changed from NEC Article 215 (informational note on feeder voltage drop) to NEC 215.4(A)(2), Informational Note No. 2. The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50426: explanation revised. The answer did not change. Reason: explanation now says the 5 percent figure is an informational recommendation, not a mandatory limit.
  • Question O50420: code reference changed from NEC Article 215 (feeder equipment grounding conductor) to NEC 215.6. The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50420: explanation revised. The answer did not change. Reason: explanation no longer implies that a separate wire is always required.
  • Question O50421: code reference changed from NEC Article 215 (ground-fault circuit-interrupter protection for personnel) to NEC 215.9. The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O50421: answer option wording revised. The answer did not change. Reason: keyed option now says the GFCI must be listed, as the rule states.
  • Question O50421: explanation revised. The answer did not change. Reason: explanation now limits the permission to the referenced GFCI provisions.
  • Question O52076: code reference changed from NEC 215.3 to NEC 215.5 (215.3 in the 2023 NEC). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O52076: question text revised. The answer did not change. Reason: stem now states that only the overcurrent device rule is applied, since conductor capacity is not given.
  • Question O52076: worked solution revised. The answer did not change. Reason: solution givens now match the revised stem.
  • Question O54029: code reference changed from NEC 215.2(A)(1) to NEC 215.4(A)(1) (215.2(A)(1) in the 2023 NEC). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O54029: question text revised. The answer did not change. Reason: stem now states that only the conductor ampacity rule is applied, since parallel installation and overcurrent device sizing are not part of the question.
  • Question O54029: explanation revised. The answer did not change. Reason: explanation now states the 125 percent conductor rule in plain terms.
  • Question O54029: worked solution revised. The answer did not change. Reason: solution givens now match the revised stem.
  • Question O50422: code reference changed from NEC Article 215 (diagrams of feeders) to NEC 215.13. The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O51219: code reference changed from NEC Article 225 (overhead conductor size) to NEC 225.6(A). The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O51218: code reference changed from NEC Article 225 (support of overhead conductors) to NEC 225.26. The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O51218: explanation revised. The answer did not change. Reason: explanation drops the holiday-lighting allowance, which was not confirmed for 225.26 in the 2026 reading.
  • Question O50212: code reference changed from NEC 225.32 to NEC 225.31(B) (225.32 in the 2023 NEC). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50212: question text revised. The answer did not change. Reason: stem now asks only about an inside disconnect, since inside and outside locations have different rules.
  • Question O50212: answer option wording revised. The answer did not change. Reason: keyed option no longer merges the inside and outside location rules.
  • Question O50212: explanation revised. The answer did not change. Reason: explanation now separates the inside rule from the outside rule.
  • Question O51071: code reference changed from NEC Article 225 (feeder disconnecting means) to NEC 225.33(A). The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O51071: question text revised. The answer did not change. Reason: stem now asks about one supply, since the six-device limit applies per supply.
  • Question O51071: explanation revised. The answer did not change. Reason: explanation now states that the limit is per supply.
  • Question O51072: code reference changed from NEC Article 225 (identification of feeders) to NEC 225.37. The answer did not change. Reason: citation now points to the specific 2026 NEC section instead of the general article.
  • Question O51072: question text revised. The answer did not change. Reason: stem now excludes the industrial-installation exception the code allows.
  • Question O51072: answer option wording revised. The answer did not change. Reason: keyed option now includes other services and the area served, as the rule requires.
  • Question O51072: explanation revised. The answer did not change. Reason: explanation now lists everything the plaque or directory must identify.
  • Question O50044: code reference changed from NEC 210.8(B) to NEC 210.8(B)(2). The answer did not change. Reason: citation now points to the specific 2026 NEC list item instead of the whole subsection.
  • Question O50429: code reference changed from NEC 210.8(B) to NEC 210.8(B)(5). The answer did not change. Reason: citation now points to the specific 2026 NEC list item instead of the whole subsection.
  • Question O51078: code reference changed from NEC 210.8(A) to NEC 210.8(A)(9) and the 210.8 measurement rule. The answer did not change. Reason: citation now points to the specific 2026 NEC subsection instead of the whole section.
  • Question O51078: question text revised. The answer did not change. Reason: stem now states the distance the way the code measures it, from the top inside edge of the bowl along the shortest cord path.
  • Question O51078: explanation revised. The answer did not change. Reason: explanation now uses the 2026 measurement method.
  • Question O51290: code reference changed from NEC 210.8(A) to NEC 210.8(A)(11) and the 210.8 measurement rule. The answer did not change. Reason: citation now points to the specific 2026 NEC subsection instead of the whole section.
  • Question O51290: question text revised. The answer did not change. Reason: stem now gives the shortest cord path instead of a straight-line distance and asks only about the bathtub requirement.
  • Question O51290: explanation revised. The answer did not change. Reason: explanation now uses the 2026 measurement method and notes that AFCI and location rules still apply separately.
  • Question O50038: code reference changed from NEC 210.12(E) to NEC 210.12(E)(1)-(2) and Exception; 210.12(A). The answer did not change. Reason: citation now names both permitted methods and the exception.
  • Question O50038: answer option wording revised. The answer did not change. Reason: keyed option now presents the two methods as examples rather than the complete list.
  • Question O50038: explanation revised. The answer did not change. Reason: explanation no longer presents the two named methods as the only permitted ones.
  • Question O51081: code reference changed from NEC 210.12 to NEC 210.12(D)(1). The answer did not change. Reason: citation now points to the specific 2026 NEC list item instead of the whole section.
  • Question O51081: explanation revised. The answer did not change. Reason: explanation now notes that the 2026 rule also covers 10-ampere circuits.
  • Question O51280: code reference changed from NEC 210.12 to NEC 210.12(A)(4)(b) (same limits in 210.12(A)(3)(b)). The answer did not change. Reason: citation now points to the specific 2026 NEC subsection instead of the whole section.
  • Question O51280: question text revised. The answer did not change. Reason: stem now names the specific AFCI method, copper conductor and continuous wiring that the length limit applies to.
  • Question O51280: explanation revised. The answer did not change. Reason: explanation now ties the length limit to the specified methods instead of all AFCI arrangements.
  • Question O50042: code reference changed from NEC 210.11(C)(4) to NEC 210.11(C)(4), Exceptions No. 1 and No. 2. The answer did not change. Reason: citation now names both exceptions to the garage circuit rule.
  • Question O50042: question text revised. The answer did not change. Reason: stem now rules out the single-bay exception so the keyed option is complete.
  • Question O50042: explanation revised. The answer did not change. Reason: explanation now mentions the single-bay exception and why it does not apply.
  • Question O50323: code reference updated to the 2026 NEC location 120.141 and Table 120.141 (was 550.31); the 2026 NEC moved mobile home park demand factors to Article 120, and the 25% factor for 20 lots is unchanged. The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50029: code reference narrowed to the 2026 NEC subdivision 120.140(A)(1), which holds the 3 VA per square foot lighting load for a mobile home (was 120.140). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50052: code reference updated to the 2026 NEC location 406.12(D)(3) (was 406.4(D)(3)). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50166: code reference updated to the 2026 NEC location 406.12(D)(2) (was 406.4(D)(2)). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50245: code reference updated to the 2026 NEC location 406.12(D)(4) (was 406.4(D)(4)). The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50199: code reference updated to the 2026 NEC location Table 120.130(A) (was 551.73(A)); the 2026 NEC moved RV park demand factors to Article 120, and the 42% factor for this number of sites is unchanged. The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50029: code reference updated to the 2026 NEC location 120.140 (was 550.18(A)(1)); the 2026 NEC moved mobile home load calculations to Article 120. The answer did not change. Reason: section renumbered in the 2026 NEC.
  • Question O50071 (dwelling demand load): the question used 3 VA per square foot for dwelling general lighting. The external review found that the 2026 NEC dwelling unit load is 2 VA per square foot. The stem now states 2 VA per square foot and the correct answer is 4,925 VA (it was 5,625 VA).
  • Question O50101 (dwelling general lighting load): the question used 3 VA per square foot. The external review found that the 2026 NEC dwelling unit load is 2 VA per square foot. The stem now states 2 VA per square foot and the correct answer is 4,800 VA (it was 7,200 VA).
  • Question O50238 (range hood cord length): the keyed answer said 18 to 36 inches. The external review read the 2026 NEC limit as 18 inches to 4 feet. The answer now reads 18 inches to 4 feet.
  • Question O50084 (mobile home demand load) is withdrawn: the external review could not confirm whether the mobile-home rule or the 2026 Article 120 unit load applies, so we removed it instead of guessing.
  • Question O50310 (retail lighting load for a feeder) is withdrawn: the external review found the 125% step does not belong in the 2026 load calculation, which conflicts with how the question was worded, so we removed it instead of rewording it unchecked.
  • Question O50014: code reference corrected to the 2026 NEC location 404.2(C) (was Article 406, Part III (grounded conductor at switch locations; 404.2(C) in the 2023 NEC)). The answer did not change.
  • Question O50016: code reference corrected to the 2026 NEC location 110.29 (was Article 100 (In Sight From); NEC 430.102). The answer did not change.
  • Question O50027: code reference corrected to the 2026 NEC location 120.54 (was 120.54 (220.54 before the 2026 NEC)). The answer did not change.
  • Question O50037: code reference corrected to the 2026 NEC location 210.8(A)(12) (was 210.8(A)(10)). The answer did not change.
  • Question O50038: code reference corrected to the 2026 NEC location 210.12(E) (was 210.12(D)). The answer did not change.
  • Question O50045: code reference corrected to the 2026 NEC location 300.7(D)(1) (was 300.5(D)(1)). The answer did not change.
  • Question O50047: code reference corrected to the 2026 NEC location 300.7(B); 334.12(B) (was 300.5(B); 334.12(B)). The answer did not change.
  • Question O50051: code reference corrected to the 2026 NEC location 300.9(A) (was 300.7(A)). The answer did not change.
  • Question O50077: code reference corrected to the 2026 NEC location 250.122(D) (was 250.122(B)). The answer did not change.
  • Question O50102: code reference corrected to the 2026 NEC location Table 120.45 (was Article 120 (lighting load demand factors; 220.45 in the 2023 NEC)). The answer did not change.
  • Question O50147: code reference corrected to the 2026 NEC location 210.12(B) (was 210.12(A)). The answer did not change.
  • Question O50156: code reference corrected to the 2026 NEC location Table 300.7(A), Column 1 (was 300.5(A), Table 300.5). The answer did not change.
  • Question O50159: code reference corrected to the 2026 NEC location 300.16(A) (was 300.14). The answer did not change.
  • Question O50206: code reference corrected to the 2026 NEC location 250.24(D) (was 250.24(C)). The answer did not change.
  • Question O50214: code reference corrected to the 2026 NEC location 210.8(A)(6) (was Article 210 (GFCI protection for dwelling-unit receptacles; 210.8(A) in the 2023 NEC)). The answer did not change.
  • Question O50228: code reference corrected to the 2026 NEC location 300.15(B) (was 300.13(B)). The answer did not change.
  • Question O50232: code reference corrected to the 2026 NEC location Table 300.7(A), Column 3 (was 300.5 (minimum cover for underground installations)). The answer did not change.
  • Question O50251: code reference corrected to the 2026 NEC location 404.9 (was 404.7). The answer did not change.
  • Question O50257: code reference corrected to the 2026 NEC location 680.71 and 680.75 (was 680.71). The answer did not change.
  • Question O50313: code reference corrected to the 2026 NEC location 120.14(I) and Table 120.47 (was Article 120 (non-dwelling receptacle load demand; 220.44 in the 2023 NEC)). The answer did not change.
  • Question O50054: code reference corrected to the 2026 NEC location 410.16(D)(1) (was 410.16(C)(1)). The answer did not change.
  • Question O50162: code reference corrected to the 2026 NEC location 358.24(B) (was 358.26). The answer did not change.
  • Question O50170: code reference corrected to the 2026 NEC location 410.16(C) (was 410.16(B)). The answer did not change.
  • Question O50187: code reference corrected to the 2026 NEC location 550.51(A) (was 550.32(A)). The answer did not change.
  • Question O50234: code reference corrected to the 2026 NEC location 312.4(A) (was 312.2). The answer did not change.
  • Question O50237: code reference corrected to the 2026 NEC location 410.71 (was 410.130(G)). The answer did not change.
  • Question O50244: code reference corrected to the 2026 NEC location 406.12(A) (was 406.4(A)). The answer did not change.
  • Question O50256: code reference corrected to the 2026 NEC location 550.51(C) (was 550.32(C)). The answer did not change.
  • Question O50103 (single-phase service load in amperes): the explanation said 120 A comes from adding 25%; 100 x 1.25 is 125 A. The explanation now gives the arithmetic behind each wrong option. The correct answer (100 A) did not change.

Checks before publication

  • 2 calculation questions added after a check against the 2026 NEC and a separate review pass (one rewritten for the 2026 RV-site receptacle rule, one with its 2026 code location). The set now has 1,002 questions and 10 full two-part mocks.
  • 753 questions added after a separate review pass: 624 passed and 129 were corrected before release. The set now has 1,000 questions, 9 full two-part mocks with no question shared between mocks, and step-by-step solutions for all 297 calculation questions.
  • 69 questions added after a check of 85 new drafts: 65 passed, 4 were corrected (three code references set to the level that could be confirmed, one stem now states the welder duty cycle) and 16 were removed because they repeated an existing question. Step-by-step solutions were added for 58 more calculation questions after the same check (4 corrected: three for rounding or arithmetic wording, one rebuilt for a corrected question).
  • 95 questions added after a check of 100 drafts: all references moved to 2026 NEC numbering, three questions reworded to stand alone, one explanation corrected, and 5 drafts removed (four repeated an existing question, one depended on a GFCI location list that could not be confirmed for the 2026 NEC).
  • Step-by-step solutions for the 26 Calculations questions were checked before release: all 26 passed; lookup paths are taken only from each question's own checked NEC reference.
  • 55 questions were added after a check: all 55 passed.
  • Check of the first 30 questions: 22 passed and 8 were corrected before publication (2026 NEC renumbering where Article 220 became Article 120, a switch rule moved to Article 406, PV disconnect references, one branch-circuit reference, and one question's room changed from a hallway to a bedroom).

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Not a licensed Professional Engineer in Texas or any U.S. state. Does not offer engineering services. Exam-prep education only.