So I want to measure the resistance of an unknown resistor.
My setup is shown with the circuit diagram and I use the variable resistor to collect a range of readings of current $I$ through and potential difference $V$ across the unknown resistor.
I get my table of values of $V$ and $I$.
Then there are two options:
- plot a graph of $V$ against $I$ using my values. The resistance of the resistor is simply the gradient of this graph.
- work out the resistance for each set of results. Discard any glaring anomalies and then calculate the mean.
I am always told that the first option is better. However I am not too sure why.