Read the potential difference shown in Fig. 2.2 and enter the reading in Table 2.1 on page 6.
Calculate the current $I$ for each length $L$ listed in Table 2.1 using $I = \frac{V}{10}$. Enter your results in Table 2.1. Calculate $\frac{1}{I}$ for each length $L$ listed in Table 2.1 and enter these in Table 2.1. Put the units in the top row of the table.
On the grid on page 7, draw a graph of $\frac{1}{I}$ on the y-axis against $L$ on the x-axis. Begin both axes at the origin $(0,0)$.
Draw the straight line of best fit. Extend the line so that it meets the y-axis.
Determine the gradient $G$ and y-intercept $c$ of this line. Show clearly on the graph the values you choose and show your working.
Theory gives $R_w = \frac{1000\,G}{c}$, where $R_w$ is the resistance of the wire. Use your answers from part (b)(iii) to find $R_w$. Show your working.