Flexible Cords practice questions

Correct: C — 400.5(A)

400.5(A) hosts Table 400.5(A)(3), the adjustment factors for more than three current-carrying conductors in a flexible cord or cable. 400.5(B) only addresses not exceeding the insulation's ultimate temperature limit, and 400.4 just lists cord/cable types, neither contains ampacity or derating tables.

Correct: C — 610 mm (24 in.)

400.6(A) sets the maximum spacing for durable surface markings on listed flexible cord types at 610 mm (24 in.). The 305 mm, 914 mm, and 1.2 m spacings are all longer or shorter values that don't match this specific requirement.

Correct: B — Running the cord through a doorway to reach a portable tool

400.12(3) specifically bars running flexible cords through doorways, windows, or similar openings. Pendants, portable-equipment connections, and readily removable appliance cords are examples of permitted uses under 400.10, not prohibited uses under 400.12.

Correct: B — No, flexible cords are restricted to the specific uses listed in 400.10(A)

400.10(A) gives a closed list of permitted uses for flexible cords — none of which is substituting for fixed wiring through a wall. Ampacity rating and concealment don't override this restriction; the use itself has to match the list.

Correct: C — Continuous green, or continuous green with one or more yellow stripes

Per 400.23, continuous green or continuous green with one or more yellow stripes shall not be used for anything other than the equipment grounding conductor. White/natural gray identifies grounded conductors under other Code provisions, and black is a common ungrounded-conductor color, not grounding-conductor identification.

Correct: D — A readily distinguishable solid color other than white or gray

Per 400.22(A), when one conductor's braid is finished white or gray to mark the grounded conductor, the other conductor(s) must finish in a readily distinguishable solid color — white is reserved for the grounded conductor, so it can't also appear on another conductor's braid.

Correct: B — 400.22(C)

400.22(C) covers colored insulation for grounded-conductor identification, including the light-blue rule for jacketed cords furnished with appliances. 400.22(D) applies instead when the individual conductors use a colored separator rather than colored insulation, and 400.22(A) applies only to cords with braided conductors, while 400.23(B) governs equipment grounding conductor identification, not the grounded conductor.

Correct: C — 6 AWG copper or larger with flexible stranding

400.44(A) requires conductors to be 6 AWG copper or larger and to employ flexible stranding. The 8 AWG option is too small, copper-clad aluminum with standard stranding fails both the material and stranding requirements, and stranding type is specifically mandated, not left open.

Correct: B — Sunlight resistance rating

400.52(A) requires maximum rated voltage, type letters, manufacturer identification, AWG/circular mil size, and maximum operating temperature. Sunlight resistance is only an optional marking permitted under 400.52(B), not a required one.

Correct: D — No, these cables cannot substitute for a structure's fixed wiring

400.43(1) specifically prohibits using portable power feeder cables over 2000 volts as a substitute for the fixed wiring of a structure, regardless of rating or raceway installation. The raceway option is also generally barred by 400.43(6) except where otherwise permitted, and duration isn't the controlling factor here.

Correct: B — It must be adequate to prevent damage to the cable during installation and handling

400.34 states the minimum bending radii shall be adequate to prevent damage to the cable during installation and handling in service — it does not set a fixed multiplier like raceway bending rules, and it is a code requirement, not just a warranty matter. Section 400.34.

Correct: A — 400.21(A)

400.21(A) requires flexible cord conductors to be copper flexible stranding sized per Table 400.4. 400.22(A) covers colored braid identification for the grounded conductor, not conductor sizing, and 400.20 covers cord labeling, not construction.

Correct: C — 400.17

400.17 requires bushings or fittings wherever flexible cords or cables pass through holes in covers, outlet boxes, or similar enclosures. 400.16 instead covers overcurrent protection sizing for flexible cords, and 400.12 lists uses not permitted — neither addresses protecting the cord jacket at a passage point.

Correct: C — Type SJO

Section 400.15 lists specific S-family cord types, including SJO, as permitted in show windows and showcases. SPT-1 and SPT-2 lamp cords are not on that list, and NM cable is a fixed-wiring cable, not a flexible cord, so it is not a valid option here.