Theory & SafetyCâu 110 / 120
A 20-ohm resistor and a 30-ohm resistor are connected in parallel. What is the total resistance?
a.50 ohms
b.12 ohms
c.25 ohms
d.10 ohms
Giải thích
For two resistors in parallel, R total = (R1 x R2) / (R1 + R2) = (20 x 30) / 50 = 600 / 50 = 12 ohms. The 50-ohm answer adds them as if they were in series, and 25 ohms averages them, but total parallel resistance is always less than the smallest branch resistance.
Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
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