A potentiometer wire AB having length L and resistance 12 r is joined to a cell D of emf ε and internal resistance r. A cell C having emf ε / 2 and internal resistance 3r is connected. The length AJ at which the galvanometer as shown in figure shows no deflection is:
(1) 11/12 L
(2) 11/24 L
(3) 13/24 L
(4) 5/12 L
