Core TradesCâu 75 / 700
A 120-volt lighting circuit runs a long distance and the fixtures at the far end appear dim. The MOST likely electrical cause and its fix is:
a.Too little load; add more fixtures
b.Excessive voltage drop on the long run; use a larger conductor size or shorten the run
c.The breaker is too large; install a smaller breaker
d.The neutral is oversized; reduce its size
Giải thích
Dim fixtures at the end of a long run indicate voltage drop from conductor resistance over distance; the remedy is upsizing the conductor (or reducing length/load) to keep drop within recommended limits, generally about 3 percent for a branch circuit. Adding load worsens drop; breaker and neutral sizing do not cause dimming this way.
Trích dẫn luật: 2025 CA Electrical Code (based on NEC)Luyện miễn phí toàn bộ 700 câu hỏi — không cần đăng ký.
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