Question

A potentiometer wire $AB$ having length $L$ and resistance $12r$ 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 fig. shows no deflection is

• A. $\frac{5}{12}L$
• B. $\frac{11}{24}L$
• C. $\frac{11}{12}L$
• D. $\frac{13}{24}L$

Answer 1

The correct option is D $\frac{13}{24}L$