Current and Resistance

In the picture above we light the bulb by ensuring that the cable is touching one end of the battery and the side of the bulb and that the bulb's bottom is touching the other end of the battery. We could have also lit the bulb by touching the cable to the bottom of the bulb and placing the side of the bulb on the battery. This works because the charge goes from the battery into the bulb and then flows out back into the battery. This keeps the flow of energy going.

We show the same thing we did above but with 2 batteries.

This is an electroscope. You touch the top bulb with an object and the two plates inside the box will move if the object has a charge.

In the video above Professor Mason shows us how the electroscope works. He introduces a charge to the rod by rubbing it with animal fur, then touches the electroscope and we see the plates move, confirming that the rod has a charge.

The picture above illustrated 2 methods where the bulb could be lit by a battery and 2 methods where the bulb would not be lit. The right most picture was something we accidentally did at first, without the fire of course. The bottom picture shows how to make the bulb light with 2 batteries.

We assumed that nothing would happen if we connected the positive end of the battery to the electroscope and we were correct. We also explain why a close circuit connection is required to light the bulb. Electrons flow into the bulb but also flow out, ensuring that it does not get full.

In the above picture we use a 4 amp bulb and battery with an old style multimeter and we illustrate the same thing we did above by creating a close circuit connection in which the bulb could light. We wanted to determine if flow of energy outside of the bulb would match flow of energy to the bulb, so we tested it at both ends, and in both situations the meter read 4 amps, meaning that they were equal, there was no energy lost.

We assumed that the charge of an electron, cross sectional area, drift velocity, and number density were required to find the charge. In the picture above we were able to find drift velocity with some givens.

Professor Mason adds a current to a wire typically found in a toaster. We wanted to see if there was any relationship between current(Amps) and potential energy (volts).

The picture above is the graph of the experiment Professor Mason performed in class. There is a linear relationship between current and potential energy.

Professor Mason also tried the same thing with the light bulb, but unfortunately the bulb kept blowing.

This is what we assumed the graph would look like and we were correct. We also assumed that the opposite relationship would be linear, which was also correct.

We determined that if the diameter of a cable goes up the resistance goes down. Resistance also goes up with length. We also determined that material used also factors into how much resistance there is.