Gradient/Slope of a Resistance vs Length Graph (AS Level)?

I would like to know what the the gradient of a resistance(y-axis) vs length(x-axis) graph would represent and how I could use this graph to find the resistivity of the wire. Also what would the area under the graph represent?

Thanks

Reply 1

jaroc

Original post by xtheghidx

So, your graph would be of the form:

r=al+b

(although generally for the length of 0 resistance should be 0 as well, non-zero b coefficient would indicate a systematic error).

We know that

r=\rho \dfrac{l}{A}

where

A

is the cross sectional area of the wire.

So we find that coefficient a is

a=\dfrac{\rho}{A}

.

I can't think of anything that could be represented by the area under the graph. It does have the dimension of resistivity, but it certainly does not represent it.

Spoiler

Reply 2

xtheghidx

This helps so much. Thanks