Thirteenth Day

Spring 2015
14th of April's Class

The first experiment we conducted was done with two batteries, and two light bulbs. We were tasked to design a circuit that would create the brightest glow from these bulbs, using all the items given. We designed the brightest glow by having the batteries set up in a series. Image is shown below.

The next part of the experiment assigned us to design a circuit that would create the dimmest glow. To do that, we gave the batteries a parallel set up.

The reasoning for the two different results from the series and parallel, is that they were designed to calibrate the set up differently. The parallel set up causes a higher rate of Current while series' set up creates a higher Voltage. A higher voltage means that there is a higher potential energy in the system, therefore a larger amount of work will be done.

In simple drawings, the image above is what the circuit looked like.

Below, we were taught how to draw circuits in simple sketches with symbols. The upper half of the image below are the legends to what each symbol meant. While the lower half is the representation of the series and parallel circuits we designed in simple sketch form.

In the image below, the words written in green marker is the variables we need to find the change in the temperature of water. Words written in blue is the demonstration that Professor Mason is doing to show us how the Voltage affects the temperature of water.

First he would use a water heater to heat water constantly for 2 minutes, and graph that. Then, he would double the voltage, and graph the next two minutes.

This is the resultant graph of the first two minutes (before the doubled voltage):

This next one is the resultant graph of the next two minutes (after the doubled voltage)

In the graph above, there are two distinct graphs. The red graph is from before the doubled voltage, while the blue is the graph from after the doubled voltage. We can clearly observe an increase in the slope of the blue graph, comparing to the red. We were then asked to estimate the factor that the slope would be increased due to the doubled voltage. After working out some equations, the image below shows how we derived that the slope would be increased by a factor of about 4.

Professor Mason then gave us a refresher on Kinematics. Relative to Gravitational field, work done in perpendicular motion from the direction of the field is always 0.

In the image below, we were asked to rank the magnitude of work done in increasing manner, from the different angles presented to us. From this, we learnt that the work done relative to the field, ranges from a multiplication factor of 0 (perpendicular) to 1 (parallel).

We derived an equation to find another definition for Voltage in terms of charge and radius. We start of by the definition of potential energy of an electrical system is the negative of its Work Done (circled in pink). It can also be defined by the equation written below (circled in yellow). Potential energy of electrical system can be defined with the integration of charge multiplied by Energy of electrical system. Voltage is then derived into the integral of Electrical field over distance, which would ultimately lead us into the definition of voltage being (kQ)/r.

For the last part of class, we had to complete a VPython assignment. We were tasked to predict the resulting graph from the code given above. Our predicted resultant graph is this image below, along with the hand calculated Voltage total from the given respective observation points.

As the last task for the day, we were asked to code a similar coding with the image above, by adding another charge and also 1 more observation point. The image below is part of the coding we made for the program. We would then calculate its total voltage from the 3 different observation points by requesting VPython to do the calculation for us.

This picture below is our calculation by hand: