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

Step-by-step solution

V_ A B = Equivalent emf of two batteries in parallel. aligned & = E₁ / r₁+E₁ / r₂ 1 / r₁+1 / r₂ & = (6 / 1)+(3 / 2) (1 / 1)+(1 / 2) =5 ~V aligned Answer is 5 . Analysis of Question (i) In my opinion this is the simplest question of JEE 2011. (ii) When no current is drawn from this equivalent battery, then V_ A B =V=E Otherwise, V=E ir (iii) Similar type of question was asked in JEE 1981 and cancelled paper of JEE 1997.