Goal: To visualize an electric potential interaction between two electrodes and to sketch the resulting configuration as it creates a 2-dimensional electric field that can be used to map 2-D, equipotential lines.

Data and results:

Parallel Plate

Two Point

Point and Plate

Faraday Ice Pail

Insulator and Conductor in a Field

Analysis: The reason why equipotential lines near a conductor’s surface are parallel to it is because when there is a charged surface, as it is along the conductor’s surface, it makes it so that the electric field lines go parallel to it. As voltage goes up along the electric field lines, there will always be points that are parallel to these lines at which there is no voltage, or rather the equipotential line shows up perpendicular to the electric field lines. And why are the equipotential lines near the insulator surface perpendicular to the surface? Think of the way a topographical map looks, the steeper a hill the more the lines will indicate that it is so, just like with equipotential lines, the “steeper” the voltage is near an insulator, the more the equipotential lines will show up as going perpendicular to how the electric field lines are going.

For the parallel plate and two point examples, when the lines had less distance between them, the electric field strength was constant, but as the lines grew apart, the electric field strength went down and subsequently so did the equipotential lines distance from each other increased because there was a less steep gradient of voltage value.  

Conclusion: This lab provided a visualization of the way electric field lines behave around insulators and conductors, as well as how their being perpendicular or close together indicates the surrounding voltage and direction of equipotential lines.  Basically a charged surface is connected to an electric field which is shown by the lines that are perpendicular to that charged surface. The voltage “slope” if one can visualize it that way (like in the topographical map) is corresponding to these lines. Each line indicates that there will be points that will pop up as the same potential, and hence why there ends up being equipotential when the voltage goes to zero, and this is when all these points are at ninety degrees or perpendicular to the force lines. And then when there are lines of equipotential, just like with the topographical map, the closer the line are to each other (the more “squished together” they are), the steeper the voltage “slope” or voltage gradient will end up being. And if the voltage gradient is more sloped or steeper than the insulator can stand, then the insulator will break down (think of how lightning has to break down the insulator that the Earth’s atmosphere has that would inhibit anything less than a huge amount of voltage between opposite charges).