Two batteries A and B each of e.m.f. 2V are connected in series to an external resistance `R = 1 Omega`. If the internal resistance of battery A is `1.9 Omega` and that of B is `0.9 Omega`. What is the potential difference between the terminals of battery A ?

Explanation

Total current through the circuit `i=("voltage")/("resistance resistance")`

`=(4)/((1+ 1.9+ 0.9)) =4/(3.8) A`
potential difference of A, `V_A= epsi - ir`,
`=2-4/(3.8)xx1.9 = 2-2 =0`