发布时间:2025-02-02 17:56:06
首先,mm2是指电缆截面即圆的面积(平方毫米),由面积公式:
S=π * r2=3.14*1/2R2=???mm2
比如:你说得如果不是四等芯的、不带钢带的即:由4.5CM=45mm便是3*150+1*70=520mm2的电缆。按照公式计算:r=√S/π=√520mm2/3.14==45mm==4.5CM
一有钱人想花大钱包我一同事她挺漂亮身材好那男的各种钱财诱惑二十万车房钱她还是无动于衷的是因
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