4/30 Charge on Capacitors

We set up a closed circuit to charge a capacitor. We then used the charged capacitor to light a bulb without the batteries in the circuit. We measured how long it took for the bulb to go completely unlit and graphed our results.

The above two graphs are of the potential electric energy of the capacitor vs. time. The first graph is when the capacitor is discharging and the second graph is when the capacitor is charging. 

Using the data we found from the previous lab, we derived a formula that could calculate the charge if given time, capacity, and resistance. The formula we derived in red matches the format of the best fit curve on our graphs. We also found the formula for the time constant.

We found that current has an inversely proportional relationship with time. We used the formulas we derived from the experiment to assist us in solving the problem. We were asked to find the amount of time it took the current to go through the resistor.

We then calculated how long it would take for the circuit to charge a single electron. We replaced V with Q/C so that we could solve the problem and found that it takes 148.7 seconds to charge an electron with this circuit.

This is a demonstration of what happens to capacitors when they are overcharged. We hid behind a blast shield because the explosion is dangerous. Mason also told us that he had experienced a time during the robotics competition when a student had failed to wear protective gear and was injured by a similar explosion. This was in a way to teach us the values of being safe.