Question

O AWG copper conductor without any markings to indicate the The terminal for dh s terminal is assumed to have a minimum terminal temperature rating E. 90°C. 60°C. of: C, D. 75 C. B. 40-С. Code reference re rated branch-circuit supplies fluorescent luminaires (lighting fixtures) with a peres. All terminations are 75°C rated, there are only three current- THHW as shown in Figure 1.43 pe 10. A 20-am carrying conductors in EMT, and the conductor insulation is The minimum size copper conductor permitted for this branch-circuit i A 16AWG, C. 12AWG. B. 14 AWG E. 8 AWG. D10 AWG. Code reference 11. Receptacles rated 120 volts and 15- or 20-amperes installed on construction sites for the purpose of supplying power for portable equipment are not permitted to be: A of the grounding type. B. GFCI protected. C. supplied with Type NM-B Cable if the building is more than three floors in height D. supplied with Type NM-B Nonmetallic-Sheathed Cable for other tharn dwellings E. installed on branch-circuits that also supply temporary lighting. Code reference 12. An electrical panel is installed on a wall in a room of a commercial building where the distance from the floor to the structural ceiling is 15 ft (4.5 m). The distance from the floor to the top of the panelboard is 6 ft (1.8 m). An air-handling duct that will not cause dripping due to condensation is: A. permitted to be installed above the panelboard. B. permitted to be installed not less than 3 ft (900 m) above the panelboard C. permitted to be installed not less than 4 ft (1.2 m) above the panelboard D. permitted to be installed not less than 6 ft (1.8 m) above the panelboard E. permited to be installed not less than 6 ft (1.8m) above panelboard Code reference_

Answer 1

9. D
If a conductor termination does not have a marked temperature rating, 110.14(C)(1) sets the temperature rating based upon the rating of overcurrent device or conductor size.
If the conductor is size 1/0 AWG or larger, the termination is required to have a minimum rating of 75°C unless otherwise marked.

10. C

Allowable ampacity for 3 conductors in raceaway, when the terminations are rated at 75 degree celsius, for THHW copper conductor from the table would be found from the 75 degree Celsius column of Table 310.16.
Lighting load is a continuous load, therefore, the minimum conductor size, according to 210.19(A), is required to be not less than 1.25 times the load supplied, which is 1.25 x 14.2 = 17.75 Amperes.
So, per Table 310.16, a size 14 AWG copper conductor is rated 20 amperes.
Further the rule in 240.4(D) only permits a 15-ampere overcurrent device on a size 14 AWG copper conductor. So, a size 12 AWG copper conductor is the minimum permitted because the overcurrent device is rated 20 amperes (branch circuit is rated at 20 Amperes).

11. E

590.4(D) does not permit receptacles to be installed on the same circuit with temporary lighting.

12. C
Air-handling duct (Busway) is a factory-assembled metal enclosure containing electrical conductors, usually in the form of copper or aluminum bars insulated from the metal enclosure. Busway is frequently used in commercial and industrial work areas by attaching to the ceiling with a spacing not to exceed 5 ft (1.5 m)

Busway height = Ceiling height - 1.5m = 4.5 -1.5 = 3m
Panel board height = 1.8 m. So, Busway height from above the panel board = 3m -1.8m = 1.2 m.

Code Reference: 368.30