Twenty Second Day

Spring 2015
19th of May's Class

We started the day by visiting the website: Active Physics

We were fiddling around with an applet that looked like this

To be specific, it was designed to explore the flux of electromagnetic fields. We were also given questions that are associated with the applet.

The image below is our attempt at answering each of the questions:

Basically, this portion of the class functions as an exploration into the relationship that flux of magnetic field had with the other variables. These variables include the area of the loop, its orientation relative to the magnetic field, rotational frequency of the loop.

One of the most important point to take from this portion of the lesson is that the maximum flux can be obtained when the area vector of the surface is parallel to the magnetic field vector. This is due to their relationship that is characterized by a cosine graph.

Professor Mason then conducted a demonstration using a horseshoe magnet:

This demonstration serves to prove that the right hand rule works in real life. With this arrangement, we can see that the magnetic field goes upwards, as it moves from the North to the South, and the horseshoe magnet has its South side above its North side (This was marked with a red circle). One side of the metal bar, that is marked with a yellow circle, is positively charged. The other side, which is marked with a green circle is negatively charged. Therefore this generates a current that moves from the yellow side to the green side. Causing the copper shaft to move away from the horseshoe magnet.

The current was then reversed, and this is a video of what happened:

Then, we went back to the website that we were working on earlier, and continued into another set of exploration:

The diagram this time mimics the demonstration that Professor Mason did earlier. The questions below are all related to the diagram shown in the image above.

The image right below is our attempt at answering the questions.

The exercise is still discussing about the relationship of flux to other variables. However, the variables this time are a bit different. The variables here are the magnetic field, current and electromotive force, their magnitudes and their orientations relative to each other.

The professor then introduced us to inductors. Inductors are similar to capacitors in the sense that both of them stores energy. However, capacitors store energy in an electric field while inductors store energy in magnetic field. Also, capacitors maintain a constant voltage, while inductors maintain a constant current. They function only within alternating current or voltage. As inductors uses magnetic field to store energy, its form is that of a coiled wire. Capacitors' shape is that of two plates bearing opposite charges.

The image below describes the calculation process to derive the formula for Induction.

We were then posed a question by Professor Mason. What happens to the voltage if there was to be an instantaneous jump in a circuit's current. The answer was that the voltage would leap to positive infinity instantaneously too. The image below, shows the graph related to this question marked in yellow circle. 

Then, we went back to the Active Physics website, and did another set of questions.

The questions are the same as the previous ones. It is still about flux, but with different variables. This time it has to do with Voltage, Resistance, Current, and time.