Question

1.电阻R1=7欧,R2=5欧,串联后接在12V电源两端.求:(1)此时电路总电阻 (2)通过R1的电流 (3)R2的电

Answer 1

1、(1) R=R1+R2=7欧+5欧=12欧

(2)I=U/R=12V/12欧=1A

(3)U2=IR2=1A*5欧=5V

2、(1) U=U1=I1R1=0.4A*20欧=8V

(2)R2=U/I2=U/（I-I1）=8V/（0.6A-0.4A）=40欧姆

3、I=U/R=6V/12欧=0.5A

R1=U1/I=（U-U1）/I=（9V-6V）/0.5A=6欧姆

4、I2=I1=U1/R1=1V/2欧=0.5A

U=I（R1+R2）=0.5A*（2欧+3欧）=2.5V