Current, Voltage and Resistance

The class began with a video about new college graduates and how most of the engineering majors could not light a light bulb with just a battery, a wire and of course a light bulb. The reason behind why most graduates could not accomplish such a feat is because they have not received the proper education or they just never got anything out of their classes. Mason decided to let the class try so that we are not caught off guard like those students were. Unlike them, we were successful as shown in the picture below.

The reason why the students did not succeed was because most did not have a closed circuit. A closed circuit is crucial because otherwise the electrons would not flow from one terminal to the other since the ends are not together. In order for the light bulb to light, the circuit needs to be closed which allows the flow of electrons to connect with the least amount of resistance because air has a high resistance value meaning that the electrons would not be able to connect.

Then Mason asked the class to show two set-ups where lighting up a light bulb would light up and two more where the light bulb would not. We then explained why was it that the light bulbs did not light and we answered that it was because the electricity did not flow through the filaments.

 Then we moved on to the current of a closed circuit. We were able to measure the value of the current by using an ammeter and the same set-up as before for the closed circuit. The current was measured in Amps. A picture of the set-up is shown below.

We continued with the topic of current and added voltage and power to the equation which all falls into the equation of P=IV or power is equal to current times voltage. The picture below shows the different units used for each of the variables. We also solved an easier problem involving finding the power using a known voltage value and a known current.

Finally, we ended the day by talking about drift velocity as well as the relationship between voltage and current. We found that the current is the same as the change of current over the change in time. Again we solve an easy problem involving finding the drift velocity through a wire. By knowing what kind of wire it was and having known values we plugged them in into the equation and solved for the drift velocity. We also found that the voltage is equal to the current times a constant, which is resistance measured in Ohms and is also referred to Ohm's Law or V=IR

Overall, the main focus of the class was to introduce us to electricity by learning about closed circuits, voltage, current, power and learning about Ohm's law and resistance.