Mon. Week 7, April 7: Ohm's Law

On this day in class, we temporarily abandoned the topic of charge and its behaviors in order to start going over the subject of circuit fundamentals. In particular, were went over the ways in which an electrical circuit's voltage, current and resistance were all related to each other.


For the first experiment of the day, our groups collected data from an voltmeter and ammeter attached to a circuit with a fixed resistance and voltage. Data was taken from numerous voltage settings. The circuit was made up of a power supply and a single resistor of wound up wire.

The collected values were inputted into a spreadsheet where they were then used to generate a graph that turned out to be linear in nature. We then came to the conclusion that the slope of the volts vs amps graph is the value of the resister's resistance. After realizing this, we then compared our values to another groups, compared our resisters, and drew conclusions based on the physical qualities of the resistor and its corresponding resistance. We discovered that the length of the wire used to make the resistor was proportional to the resistance.

We expanded on this concept in the next lab experiment, which consisted of measuring the  resistance of a multitude of coils with different lengths. After generating a graph for resistance vs. length, the data showed a linear and proportional relationship between resistance and wire length, confirming our observations from the previous lab.