∵R3=R4=4Ω
∴R‘=(R3+R4)×R2/R3+R4+R2=4Ω
∴I1=E/R1+R’=10A
∴U(R‘)=R’/R‘+R1 ×E=40V
I2=U(R’)/R2=5A
I3=U(R‘)/R3+R4=5A
综上:I1=10A,I2=5A,I3=5A
∵R3=R4=4Ω
∴R‘=(R3+R4)×R2/R3+R4+R2=4Ω
∴I1=E/R1+R’=10A
∴U(R‘)=R’/R‘+R1 ×E=40V
I2=U(R’)/R2=5A
I3=U(R‘)/R3+R4=5A
综上:I1=10A,I2=5A,I3=5A