CGPET 2018 Solved Paper

∴ Seven identical cells each of emfE and internal resistance r are connected as shown in the figure below.
∵ VAB=E−Ir ........(i)
Applying KVL in the loop,
−E+Ir−E+Ir−E+Ir−E
+Ir−E+Ir−E+Ir−E+Ir=0
⇒E=Ir .......(ii)
From Eqs. (i) and (ii), we get
VAB=Ir−Ir=0