Physics - Practical physics Question with Solution | TestHub

A potentiometer wire$\mathrm{AB}$having length$L$and resistance$12r$is joined to a cell$\mathrm{D}$of emf$\epsilon$and internal resistance$r$. A cell$\mathrm{C}$having EMF$\epsilon /2$and internal resistance$3r$is connected. The length$\mathrm{AJ}$, at which the galvanometer, as shown in the figure, shows no deflection is