$A$ cell of $emf$ $E$ and internal resistance $r$ is connected across an external resistance $R$. Plot a graph showing the variation of potential difference $(V)$ across $R$ versus $R$.

(N/A) The potential difference $(V)$ across an external resistance $R$ connected to a cell of $emf$ $E$ and internal resistance $r$ is given by the formula:
$V = I R = \left( \frac{E}{R + r} \right) R = \frac{E}{1 + \frac{r}{R}}$
Analysis of the relation:
$1$. When $R = 0$,$V = 0$.
$2$. As $R$ increases,$V$ increases.
$3$. As $R \to \infty$,$V \to E$.
The graph shows $V$ on the $y$-axis and $R$ on the $x$-axis. The curve starts from the origin $(0,0)$ and asymptotically approaches the value $E$ as $R$ increases.