欧姆定律题

问题描述:

欧姆定律题
4.将三个电阻值之比为R1:R2:R3=1:2:3的电阻并联接入电路后,通过它们的电流之比I1:I2:I3为
A.3:2:1 B.1:2:3 C.6:3:2 D.1:1:1

并联,I与R成反比
设R1=r,则R2=2r,R3=3r
I1:I2:I3=1/R1 :1/R2 :1/R3=1/r :1/(2r):1/(3r)=1/1 :1/2 :1/3=6/1 :6/2 :6/3=6:3:2
选C