According to NEC Article 300.19, at least one support method must be provided for each conductor at the top of the vertical raceway or as close to the top as practical if the vertical rise exceeds the specified values in Table 300.19(A). Therefore, the correct answer is one.

According to NEC Article 334.10, Type NM (Nonmetallic-Sheathed) cable and its associated fittings must be listed. This means they have been tested and approved by a recognized laboratory to ensure they meet specific safety and performance standards. Listing is essential for ensuring compliance with the National Electrical Code and the safety of electrical installations.

According to the NEC, particularly Article 320, AC cables and their fittings must be listed. This means they have been tested and certified by a recognized testing laboratory to meet safety and performance standards. Using listed materials ensures that installations comply with code requirements and are safe for use.

According to NEC Article 310.15, when conductors are installed in raceways or cables exposed to direct sunlight on or above rooftops, and the conduits are less than ½ inch from the rooftop, a temperature adder of 60°F must be added to the outdoor temperature. Therefore, the correct answer is 60°F.

According to NEC Article 334.30, Type NM (Nonmetallic-Sheathed) cable can be supported and secured by staples, cable ties that are listed and identified for securement, straps, or any other approved means. The flexibility in securing methods ensures that installations comply with safety standards while accommodating various installation scenarios.

According to NEC Article 314.20, in installations within or behind noncombustible walls or ceilings, the front edge of a box, plaster ring, extension ring, or listed extender employing a flush-type cover must be set back no more than 1/4 inch from the finished surface to ensure compliance and safety.

According to NEC Article 300.7, conduits or raceways that may allow moisture to contact live parts must be either sealed or plugged at either or both ends to ensure protection against moisture intrusion. Therefore, the correct answer is a or b.

According to NEC Article 314.15, drainage openings that are between 1/8 inch and 1/4 inch in diameter are allowed in boxes or conduit bodies that are specifically listed for use in damp or wet locations. Therefore, the correct answer is Listed.

According to NEC Article 320.23(B), armored cable (AC) can be unsupported and unsecured for lengths up to 6 feet when used to connect recessed luminaires or equipment within an accessible ceiling. This allowance facilitates installation in areas where additional support may not be feasible, while still adhering to safety standards.

According to NEC Article 300.7, raceways must indeed be provided with appropriate fittings, such as expansion, expansion-deflection, or deflection fittings, to effectively manage thermal expansion, deflection, and contraction. Therefore, the correct answer is True.

Unless otherwise specified, the applicable product standards evaluate the fill markings covered in 314.28(A)(3) based on conductors with Type XHHW insulation.

According to NEC Article 300.5, for locations not specifically identified in Table 300.5, a lesser cover depth than required in Column 5 may be allowed if specified in the installation instructions of a listed low-voltage lighting system. Therefore, the correct answer is listed.

According to NEC Article 334.30(B), nonmetallic-sheathed cable is permitted to be unsupported when it is fished between access points through concealed spaces in finished buildings or structures where supporting is impractical. Additionally, it can be unsupported if it is not more than 4 1/2 feet from the last point of support to the connection point of a luminaire or other electrical equipment, provided both are located within an accessible ceiling in one-, two-, or multifamily dwellings. This flexibility ensures compliance with safety standards while accommodating various installation conditions.

According to NEC Article 310.15, if cables with more than 20 current-carrying conductors are installed longer than 24 inches without proper spacing, stacked, or supported on bridle rings, a 60 percent adjustment factor must be applied to the ampacity of the conductors. Therefore, the correct answer is 60.

NEC Article 314.27 specifies that boxes used at luminaire or lampholder outlets in a ceiling must be designed to support a luminaire weighing a minimum of 50 lb to ensure adequate safety and structural integrity.

According to NEC Article 314.23, boxes can be secured to structural members using nails or screws. Both methods are acceptable as long as the installation complies with safety standards.

According to NEC Article 300.7, when raceways or cables are exposed to direct sunlight on or above rooftops, they must be installed a minimum distance of 7/8 inches above the roof to ensure proper protection and performance. Therefore, the correct answer is 7/8.

According to NEC Article 320.2, Type AC cable is defined as a fabricated assembly of insulated conductors that is protected by a flexible interlocked metallic armor. This type of cable is commonly used in various electrical installations for its durability and protective qualities.

According to NEC Article 300.7, when remote-control, signaling, and power-limited circuits are installed in a raceway subjected to different temperatures, the raceway should be filled with an approved material to prevent the circulation of warm air to colder sections. An explosion-proof seal is not required for this purpose, as there are alternative methods available.

According to NEC Article 300.5, the backfill used for underground wiring must not damage any of the components involved, including raceways, cables, and conductors. Additionally, it should not prevent adequate compaction of the fill or contribute to corrosion. Therefore, the correct answer is all of these.

NEC Article 314.23 requires that mounting holes for screws securing boxes must be approved. This ensures that the mounting method is safe and compliant with electrical installation standards.

According to NEC Article 314.28, the wiring space of enclosures for switches or overcurrent devices can include power monitoring equipment if two conditions are met: (1) the equipment must be identified as a field-installable accessory as part of the listed equipment, or it must be a listed kit evaluated for installation in the enclosure; and (2) the total area of all conductors, splices, taps, and equipment must not exceed 75 percent of the cross-sectional area of the wiring space. Therefore, the correct answer is a and b.

According to NEC Article 300.9, conductors and equipment must not be installed in environments that may cause deterioration unless they are rated or identified for such use. This encompasses being in damp or wet locations, exposure to fumes, vapors, liquids, or gases, and being subjected to excessive temperatures.

According to NEC Article 314.15, all boxes, conduit bodies, and fittings that are installed in wet locations must be specifically listed for that purpose to ensure safety and compliance with electrical code standards. Thus, the statement is true.

According to NEC Article 314.28, cabinets, cutout boxes, and meter socket enclosures can be utilized for conductors feeding through, splicing, or tapping off to other enclosures or devices as long as they meet multiple conditions: the total area of conductors at any cross-section does not exceed 40 percent, the total area of conductors, splices, and taps does not exceed 75 percent, and there is a warning label identifying the nearest disconnecting means for any feed-through conductors. Therefore, the correct answer is all of these.

According to NEC Article 314.20, in installations within walls or ceilings made of combustible materials, boxes, plaster rings, extension rings, or listed extenders must either extend to the finished surface or project from the finished surface, ensuring that they are properly installed to maintain safety and accessibility.

According to NEC Article 300.5, for locations not specifically identified in Table 300.5, a cover depth of 6 inches is permitted for pool, spa, and fountain lighting installed in a nonmetallic raceway, provided that it is limited to not more than 30V and is part of a listed low-voltage lighting system. Therefore, the correct answer is 6.

According to NEC Article 312.8, the wiring space within enclosures for switches and overcurrent devices is permitted for other wiring and equipment, provided that the limitations for specific equipment are adhered to as outlined in both 312.8(A) and 312.8(B). Therefore, the correct answer is a and b.

According to NEC Article 334.12, Type NM (Nonmetallic-Sheathed) cable is not permitted to be installed as open runs in dropped or suspended ceilings in any buildings other than one- and two-family and multifamily dwellings. This restriction is in place to ensure safety and compliance with building codes, as NM cable is primarily intended for residential applications.

According to NEC Article 300.11, raceways, cable assemblies, boxes, cabinets, and fittings must indeed be securely fastened in place to ensure safety and integrity in electrical installations. Therefore, the correct answer is True.

According to NEC Article 314.28, enclosures for switches or overcurrent devices can have conductors feeding through, provided that the wiring space at any cross section does not exceed 40 percent of the cross-sectional area of the space. Therefore, the correct answer is 40.

According to NEC Article 314.27, outlet boxes required in this section shall be permitted to support listed locking support and mounting receptacles used in combination with compatible attachment fittings, ensuring they meet safety standards.

According to NEC Article 300.5, “S” loops in underground direct burial cables and conductors are recognized for their flexibility and the need for movement due to factors like settlement or frost heaves, especially at transitions to raceways and in expansion fittings. Therefore, the correct answer is cables and conductors.

According to NEC Article 310.15(B)(7), for one-family dwellings and the individual dwelling units of two-family and multifamily dwellings, single-phase feeder conductors consisting of 2 ungrounded conductors and the neutral conductor from a 208Y/120 volt system may be sized in accordance with the specified sections. Therefore, the correct answer is 2.

According to NEC Article 314.16, if a box is equipped with one or more securely installed barriers, the volume of the box must be apportioned to each resulting space. If the barriers are not marked with their volume, they are assumed to occupy ½ cu in. for metal barriers and 1 cu in. for nonmetallic barriers. Therefore, the correct answer is one.

According to NEC Article 353.28, after cutting HDPE conduit, the ends must be trimmed both inside and outside to remove any rough edges. This ensures that the conduit can be safely joined and that the conductors will not be damaged during installation or pulling.

According to NEC Article 338.10, Types SE (Service Entrance) and USE (Underground Service Entrance) cables and their associated fittings must be listed. This means they have undergone testing and certification by an approved laboratory to meet specific safety and performance standards. This requirement ensures that these cables are suitable for their intended applications and comply with the National Electrical Code.

According to NEC Article 314.21, the gap or open space around a flush-mounted box with a cover or faceplate must be repaired to ensure that no gaps larger than 1/8 inch exist. This prevents the risk of fire hazards or exposure of electrical components.

To calculate the volume of a device box, you use the formula for the volume of a rectangular prism: $\text{Volume}=\text{Length}\times \text{Width}\times \text{Height}$ For a box measuring 3 in. x 2 in. x 2 in., the calculation is: $3\text{in}\times 2\text{in}\times 2\text{in}=12\text{cu in}$ However, for device boxes, the NEC usually provides specific volume allowances, and the answer is listed as 10 cu in due to additional considerations for internal components.

According to NEC Article 300.22, wiring methods and cabling systems listed for use in other spaces used for environmental air can be installed in ducts specifically fabricated for environmental air-handling purposes if necessary to connect equipment or devices associated with the direct action upon or sensing of the contained air, and the total length does not exceed 4 ft. Therefore, the correct answer is a and b.

According to NEC Article 330.30(A), Type MC (Metal Clad) cable must be secured and supported using staples, cable ties, straps, hangers, or similar fittings. These means must be designed and installed to avoid damaging the cable, ensuring both compliance with the code and the safety of the installation. The options “listed” and “identified” refer to the standards for fittings, which are also important but not the only methods for securing the cable.

According to NEC Article 314.27, a luminaire that weighs more than 50 lb can be supported by an outlet box that is listed for the weight of the luminaire to ensure it meets safety standards and regulations.

According to NEC Article 330.30(B), Type MC (Metal Clad) cable can be left unsupported and unsecured when fished between concealed access points in finished buildings or structures where support is impractical or when it is not more than 6 feet from the last point of support within an accessible ceiling for the connection of luminaires or other electrical equipment. These allowances are provided to facilitate installation in challenging locations while ensuring compliance with safety standards.

According to NEC Article 314.16, when a box is provided with barriers, the volume of the box must be calculated separately for each compartment created by the barriers. This ensures that the fill calculations comply with the code’s requirements for conductor volume within electrical boxes.

According to NEC Article 300.7, spare or unused raceways must be sealed with sealants that are identified for use with the specific types of insulation, including cable insulation, conductor insulation, and other components. Therefore, the correct answer is identified.

According to NEC Article 310.2, conductors that are normally used to carry current shall be of copper or aluminum unless otherwise specified by the code.

According to NEC Article 314.25, when using nonmetallic-sheathed cable or multiconductor Type UF cable, the sheath must extend at least 1/4 inch inside the box and beyond any cable clamp to provide a secure and compliant installation.

According to NEC Article 300.22, fire alarm cables, whether power-limited or nonpower-limited, that are installed in ducts, plenums, or spaces utilized for environmental air must adhere to the requirements specified in this section to prevent potential fire hazards and ensure safety.

According to NEC Article 310.15, Type XHHW-2 insulated conductors are not subject to the ampacity adjustment provisions outlined in 310.15(B)(3)(c). Therefore, the correct answer is XHHW-2.

According to NEC Article 300.5, raceways that enclose service-entrance conductors and are exposed to the weather must be approved or listed for use in wet locations and should be arranged to drain effectively.