a
$V=\varepsilon-I r$ , comparing with $y=c-m x$
$\therefore \quad$ Slope $=-r,$ internal resistance.
$V_{\max }=\operatorname{emf} \varepsilon .$ This is intercept on the $y-$ axis.
$\therefore$ Slope is negative.
$\therefore \quad I$ decreases as $R$ increases.
