Question

Two batteries of different emfs and different internal resistances are connected as shown. The voltage across AB in volt is

Answer 1

Answer: 5

$V_{AB}$ = Equivalent emf of two batteries in parallel.
$\frac{E_1/r_1+E_2/r_2}{I/r_1+I/r_2}=\frac{(6/1)+(3/2)}{(1/1)+(1/2)}=5V$
$\therefore$ Answer is 5.