Mạch nhánh & Đi dâyCâu 197 / 521
The internal cross-sectional area of 1/2" EMT is 0.304 in³ per Table 4. For three or more conductors, what usable fill area (40%) is available?
a.0.122 in²
b.0.094 in²
c.0.161 in²
d.0.304 in²
Giải thích
0.304 × 0.40 = 0.122 in². The 31% (two-conductor) area would be 0.094 in² and the 53% (single-conductor) area would be 0.161 in²; 0.304 is the full 100% area.
Trích dẫn luật: 2023 NEC Chapter 9, Table 4Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- Per Annex C, Table C.1, what is the maximum number of 14 AWG THHN conductors permitted in 1/2" EMT?
- Per Annex C, Table C.1, what is the maximum number of 12 AWG THHN conductors permitted in 3/4" EMT?
- Per Annex C, Table C.1, what is the maximum number of 10 AWG THHN conductors permitted in 1/2" EMT?
- The internal area of 3/4" EMT is 0.533 in² per Table 4. What is the 40% usable fill area for three or more conductors?
- Given a 40% usable fill area of 0.213 in² (3/4" EMT) and a 12 AWG THHN cross-sectional area of 0.0133 in² (Table 5), how many 12 AWG THHN conductors fit?
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