Q.
In the circuit shown below, the cell has an e.m.f. of 10V and internal resistance of 1ohm. The other resistances are shown in the figure. The potential difference VA−VB is
Equivalent external resistance of the given circuit Req=4Ω
Current given by the cell i=Req+rE=(4+1)10=2A
Hence, (VA−VB)=2i×(R2−R1) =22(2−4)=−2V.