I²×(R3+R1//R2)=40×0.94 I=√{37.6÷(0.6+2.4)=3.54AUab=I×R1//R2=3.54×2.4=8.496Vr=40×(1-0.94)÷3.54²=2.4÷12.53=0.19Ω电源电动势E=8.496+3.54×（6+0.19）=30.4V
