For an ordinary copper branch circuit with 20-ampere overcurrent protection, assume no special application exception and no adjustment or installation condition requiring a larger conductor. Which listed size meets the ordinary small-conductor limit?
Correct Answer
A) 12 AWG copper.
Of these choices, 12 AWG copper matches the ordinary 20-ampere small-conductor limit. Higher insulation temperature does not by itself override that limit. This assumes no special application and no conditions requiring a larger conductor; actual sizing also considers ampacity adjustments and terminations. Southwire specification 85020, page 3 footnote, identifies the 2023 NEC 240.4(D) limits. Source: https://cabletechsupport.southwire.com/en/cablespec/download_cable/?cable=21992&country=US
Why This Is the Correct Answer
Of these choices, 12 AWG copper matches the ordinary 20-ampere small-conductor limit. Higher insulation temperature does not by itself override that limit. This assumes no special application and no conditions requiring a larger conductor; actual sizing also considers ampacity adjustments and terminations. Southwire specification 85020, page 3 footnote, identifies the 2023 NEC 240.4(D) limits. Source: https://cabletechsupport.southwire.com/en/cablespec/download_cable/?cable=21992&country=US
Independent practice; verify any reference hint against the edition and category permitted for your booking. Official exam and reference-list sources →
More Class B Trade Questions
An attic furnace platform blocks required access to service panels. What should be maintained?
A panel edge called out for blocking in the structural notes is left unsupported. What should be installed?
A new dwelling laundry area has a 125-volt, 20-ampere receptacle supplied by a 120-volt single-phase circuit, without required personnel ground-fault interruption. Which protection is missing?
Which listed hazard is directly increased by carrying a forklift load high while traveling through a doorway?
A penetration through a rated gypsum wall is patched with ordinary joint compound only. What must be maintained?
A shear wall panel is installed but the specified edge nailing is missing at panel edges. What is the issue?
A service panel is installed where stored material blocks the working area. What must be maintained?
A fire-rated wall patch is finished with standard materials without matching the tested assembly. What must be preserved?
A joist hanger is installed with drywall screws instead of the fasteners specified by the hardware manufacturer. What should be corrected?
A field change includes 28 added labor-hours at $69 per hour plus $880 in material. What direct cost should be priced before markup?