Ответ:
Объяснение:
1)
r1=R/3 +2R=R*7/3
Rob=3*R*r / (3*R+r)=(3R*R*7/3)/(3*R+R*7/3)=R*1.3125=1.3125 Ом
2)
Rob= 2R*3R*4R/(2R*3R+4R*2R+3R*4R) + R + R*2R/3R=R*24/26 +R+R*2/3=R*202/78=2.59 Ом
3)
r1=2R*3R*4R/(2R*3R+4R*2R+3R*4R) = R*24/26 =0.92 Ома
r2=R1+R*2*R/(3*R)=R*5/3 =1,67 Ома
Rob=r1*r2/(r1+r2)=0.92*1.67/(0.92+1.67)=0.59 Ом