# Current as a function of voltage

- Author:
- Allen Olson

## Now let's look at this another way.

If we treat voltage as the input, it will be plotted on the horizontal axis.
If we treat current as the output, it will be plotted on the vertical.
Resistance still determines the relationship between the input and the output, and it can be changed using the slider.

In the plot above, set the resistance to 40 . What current would flow if the voltage was a) 40 V, b) -80 V, or c) 60 V?

In the plot above, set the resistance to 100 . Estimate the current shown on the graph for voltages of a) -20 V, b) 40 V, and c) 60 V.

## What's the difference?

The answers you get from graphing current as a function of voltage are the same as the answers you got from graphing voltage as a function of current. Hopefully this is not surprising. But look closely at the way the two graphs are constructed. What is the slope of the line in the plot above? Is it equal to the resistance? What is the relationship between this slope and resistance?
(*Please take some time on this, and explain fully in the space below.*)