A circuit is comprised of eight identical batteries and a resistor `R=0.8Omega`. Each battery has an emf of `1.0V` and internal resistance of `0.2Omega`. The voltage difference across any of the battery is

Explanation

Using Kirchhoff's loop law,
For the loop ABCA
`4 epsilon = 4 pi I + 0.8 I_(1) or 4 xx 1 = 4 xx 0.2 I + 0.8 I_(1)`
or `5 = I + I_(1)`
For the loop CDAC
`4 epsilon = 4 r (I - I_(1)) - 0.8 I_(1)`
`4 xx 1 = 4 xx 0.2 (I - I_(1)) - 0.8 I_(1) or 4 = 0.8 I - 1.6 I_(1)`
or `5 = I - 2 I_(1)`
From (i) and (ii), `I + I_(1) = I - 2 I_(1) or 3 I_(1) =0`
or `I_(1) = 0A and I = 5A`
Voltage across any battery `= epsilon - Ir`
`= 1.0 - 5 xx 0.2 = 1-1 = 0 V`