电流密度 ＝ 单位面积通过的电流强度：p = I/S1.S = 120*10 = 1200 (mm^2)I = 2000A p = 2000/1200 = 1.67A/(mm^2)2.S = 2.5(mm^2)I = 26Ap = 26/2.5 = 10.4A/(mm^2)
