As is described in the section on sound, the sound that we hear doesn't correspond linearly to the amount of electric power used; it instead corresponds logarithmically. A volume control knob must, therefore, have a non-linear change in resistance as well. We graphed the resistance of the potentiometer for every 5 degrees of rotation of the knob in order to measure this effect. To measure the resistance across the potentiometer, we connected a digital multimeter, set to 20 ohms (the maximum resistance of the resistor), to its center lead and to one of its two side leads. We then used a protractor to move the knob in 5 degree increments, noting the resistance every 5 degrees. This is the graph resulting from that measurement:

Here is the data used to form that graph: