并联电路题1.电阻R1R2并联在电压为6伏的电源上,通过干路的电流是0.75安,R1的阻值是12欧,求R2的阻值.2.某
1个回答

1.I1=6V/12欧=0.5A

I2=0.75A-0.5A=0.25A

由I=U/R得R=U/I=6V/0.25A=24欧

2.(1)由I=U/R得U=IR=0.2A×4欧=0.8V

(2)I2=I-I1=0.5A-0.2A=0.3A

由I=U/R得R=U/I=0.8V/0.3A=2.67欧

3.(1)I2=0.5A-0.3A=0.2A

(2)由I=U/R得U=IR=0.3A×10欧=3V

(3)由I=U/R得R=U/I=3V/0.2A=15欧