Question

What is the shape of the graph between V and I, where V is the potential difference applied between the ends of a wire and I is the current flowing through it ?

Answer 1

If a graph is drawn between the potential difference (V) and current (I), the graph is found to be a straight line passing through the origin. This shows that the current is directly proportional to the potential difference.
Calculating the slope of the graph, $\frac{V}{I}$ = $\frac{0.4}{0.1}$ = 4 = R
Thus, the ratio $\frac{V}{I}$ remains constant. The slope of the V-I diagram gives the resistance(R) of the conductor.