Question

A cell having an emf $\epsilon$ and internal resistance r is connected across a variable external resistance R. As the resistance R increases, the plot of potential difference V across R is given by.

Answer 1

$i=\frac{\epsilon }{r+R}$

$v=iR=\frac{\epsilon R}{r+R}$

$v=\frac{\epsilon }{1+\frac{r}{R}}$

here, $r=constant$