Theory & DesignCâu 90 / 110
A transformer steps 480 V down to 120 V. What is its turns (voltage) ratio?
a.2:1
b.4:1
c.1:4
d.8:1
Giải thích
Turns ratio = primary voltage / secondary voltage = 480 / 120 = 4:1.
Luyện miễn phí toàn bộ 110 câu hỏi — không cần đăng ký.
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