On Electric Potential and Electric Field

This meeting marked the first laboratory experiment for the subject.

Prior to that, though, we had the chance to chat with our lab instructor, CK Baldo, since the Physics 72.1 class was not yet finished. I appreciate moments like these because the atmosphere during these times is light and not stressful. It also helped me ease up a bit because I was quite nervous for the experiment considering that I am not a master of electromagnetism by any means.

After that, we transferred rooms and grouped together. My group, composed of myself, Mac Aydinan and Third Garcia, I must say, has good dynamics. Mac and I were lab partners last semester in 101.1 and I think that turned out well. With regards to Third, I haven't really gotten to know him that well because this is the first time that the two of us are classmates in a small class.

Before starting with the experiment, we had a prelab quiz. I had a preconception that the prelab was about the experiment at hand, but I soon found out that my preconception was wrong. The quiz was about electromagnetism in general, zooming in on point charges and electric field. There I was, panicking, because I was unsure of all of my answers. Thankfully, I managed to get an 8/10.

The experiment this meeting is entitled Electric Potential and Electric Field. To be honest, I really do not know the formulas and specifics of these two because of my weak background in this field of study. But still, as an aspiring physicist, I have to, at the very least, familiarize myself with it and, if I am done with that, learn it by heart.

For the specifics of this activity, we had to put two electrodes(spherical and line) on two sides of an electrolytic tank (which is basically a tray filled with water). Then, we grounded one electrode and connected the other to the positive terminal of a battery. We took the voltmeter readings of both electrodes and got 0 volts and 8 volts respectively. Then, by using a probe, we plotted the equipotential lines of 1 volts to 7 volts.

I think that the goal of the experiment was to show that charged objects emit electric fields and that the shape of the objects have an effect on the electric field distribution. It also showed that the electric field lines and equipotential lines are perpendicular and the reason behind this is that to move around an equipotential line entails no work done and for this to occur, the electric field must be orthogonal to it at all instances.

I learned a lot of things from this experiment. First, I learned the notion of the electric field. All charged objects emit an electric field (which when positive is directed away from the object and when negative is directed towards the object). This vector quantity (E) is equivalent to F/q. Another term I learned is the electric potential V. This quantity is electric potential energy divided by charge and is dependent only upon location in the electric field. Around a charged body is a set of curves called equipotential lines. These curves, from their namesake, are curves that have the same potential at any point. These are also perpendicular to the electric field lines. The concept of this orthogonality is not necessarily new because we discussed the occurrence of orthogonal trajectories in Math 54.

After surviving through this first experiment, I realized that I have a LOT to learn to survive the semester. But I do think that I can make it through alive if I study hard and think optimistically.