The null point of a potentiometer with a cell of emf $\varepsilon$ is obtained at a distance $l$ on the wire, then

Question

Aicharya · Accepted Answer

As we know, electric field, $E=-\frac{d V}{d r}$ Hence, emf $\varepsilon$ is also directly proportional to $l$ i.e., $\varepsilon \propto l$.

The null point of a potentiometer with a cell of emf $\varepsilon$ is obtained at a distance $l$ on the wire…