R = resistanced, resistor 電阻
p = 阻抗
L = Length
A = area section
R = (P * L) / A
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I = V/R
I = content amplifier
V = voltage
R = Resistor
=============================================
黑0棕1紅2橙3黃4綠5藍6靛7紫8灰9 白0.1 金0.01