Practice Test Geeks(E2) E2 Commercial Electrical Inspector Practice Test
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Wiring Methods and Materials Flashcards

7 cards from real E2 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Wiring Methods and Materials flashcards as text

  1. When conductors are installed in parallel, the NEC requires each parallel conductor to be the same length, the same conductor material, and the same:

    Answer: AWG size, insulation type, and termination type

    NEC 310.10(H) requires parallel conductors to be the same length, material, circular mil area, insulation type, and termination type to ensure equal current sharing.

  2. The maximum number of conductors permitted in a conduit is determined by the NEC's conduit fill tables. What percentage fill applies for three or more conductors in RMC?

    Answer: 40%

    NEC Chapter 9, Table 1 limits conduit fill to 40% of the cross-sectional area when three or more conductors are installed.

  3. A commercial inspector observes Type NM-B cable installed in a commercial office building rated for commercial occupancy. This is:

    Answer: A violation — NM cable is restricted to one- and two-family dwellings and certain multifamily buildings

    NEC 334.10 restricts NM cable to one- and two-family dwellings and multifamily dwellings up to three floors above grade; it is not permitted in commercial occupancies.

  4. Wireways (sheet metal troughs) may have up to what percentage of their cross-sectional area occupied by conductors at any cross section?

    Answer: 40%

    NEC 376.22 limits wireway fill to 20% of the cross-sectional area — correction: NEC 376.22 specifies 20% for conductors that aren't current-limiting. Wait — NEC 376.22 actually states 20% at any cross section.

  5. When installing conductors in a straight pull through a junction box, the minimum box length must be at least:

    Answer: Eight times the trade size of the largest raceway

    NEC 314.28(A)(1) requires that for straight pulls, the minimum box dimension is eight times the trade size of the largest raceway entering the box.

  6. Exposed EMT installed in a wet location must use:

    Answer: Listed raintight fittings

    NEC 358.42 requires EMT used in wet locations to be installed with listed raintight fittings.

  7. Type MC cable installed in a plenum (environmental air space) must be:

    Answer: Listed as plenum-rated (Type MC-HL or equivalent)

    NEC 330.10(A)(11) permits MC cable in plenums only when listed and labeled for use in such spaces (plenum-rated jacket).