Q. A potentiometer wire AB having length L and resistance 12 r is joined to a cell D of emf $\varepsilon$ and internal resistance r. A cell C having emf $\varepsilon /2$ and internal resistance 3r is connected. The length AJ at which the galvanometer as shown in fig. shows no deflection is :

Physics Question Image


$i = \frac{\varepsilon}{13r} $
$ i\left(\frac{x}{L} 12r\right) = \frac{\varepsilon}{2} $
$ \frac{\varepsilon}{13r} \left[\frac{x}{L} .12r\right] = \frac{\varepsilon}{2} \Rightarrow x = \frac{13L}{24} $

You must select option to get answer and solution

Questions from JEE Main 2019

Physics Most Viewed Questions

6. The spectrum of an oil flame is an example for ...........

KCET 2010 Dual Nature Of Radiation And Matter