Find the potential difference Va−Vb in the circuits shown if figure (32-E12).
Figure 32 - E12
In circuit ab baa. E2+iR2+iR3=0
iR2+i1R3=−E2
⇒iR2R1+iR3R1=−E2R1 ...(1)
andi1R3+E1−(i−i1)R1=0
E1=i1(R1+R3)−iR1
⇒E1R2=iRiR2+i1R2R3−iR1R2 ...(2)
Adding (1) and (2), we get
i1R1R2+i1R3R1+i1R2R3
=E1R2−E2R1
⇒i1(R3R1+R2R1+R2R3)
=E1R2−E2R1
i1=E1R2−E2R1R3R1+R2R1+R2R3