3个并联电阻,通过怎样的计算过程算得R1R2R3/R1R2+R2R3+R1R3

分类: 作业答案 • 2022-01-09 18:01:33

问题描述：

3个并联电阻,通过怎样的计算过程算得R1R2R3/R1R2+R2R3+R1R3
1/R1+1/R2+1/R3是怎么划成R1R2R3/R1R2+R2R3+R1R3的?请写出计算过程

答

1/R
=1/R1+1/R2+1/R3
=(R2R3)/(R1R2R3) + (R1R3)/(R1R2R3) + (R1R2)/(R1R2R3)
=(R1R2+R2R3+R1R3) / (R1R2R3)
两边同时求倒数：
那么R不就是（R1R2R3）/（R1R2+R2R3+R1R3）