A potentiometer wire $P Q$ of 1 m length is connected to a standard cell $E_1$. Another cell $E_2$ o

Question

A potentiometer wire $P Q$ of 1 m length is connected to a standard cell $E_1$. Another cell $E_2$ of emf 1.02 V is connected with a resistance ' $r$ ' and switch $S$ (as shown in figure). With switch $S$ open, the null position is obtained at a distance of 49 cm from $Q$. The potential gradient in the potentiometer wire is

Professor PC Thomas Classes · Answer

Potentiometer principle $V \propto l$.