Purpose

The purpose of this project is to investigate the relationship between the voltage loss across several resistors and the current flowing through there. I have to also determine from my data an equation describing this relationship and measure the Electrical Resistance that is measured in Ohms.

Set up 

For this lab, you will need:

• 3 Resistors connecting wires

• 1 Breadboard

• 1 Voltmeter

• 1 power supply (breadboard)

• 1 Ammeter

Here is a schematic diagram of the lab:

Procedure

1) Set the voltage of the knob to 0 volts in a clockwise direction.
2) Now, connect the resistor to the breadboard. Do not turn the power on yet. 
3) With an alligator wire, connect the power supply with the lower post of the ammeter
4) With an alligator clip, connect the positive side of the power supply to the positive terminal of the ammeter. After that, connect the black terminal of the ammeter to the top post of the resistor bracket. This will complete the circuit but, still, do not turn the power on. Now, set the ammeter to its highest reading scale.
5) Now using alligator clips, connect the positive voltmeter terminal to the top resistor post and the negative probe to the bottom resistor post. All of this will connect the voltmeter in a parallel branch circuit across the resistor. This will tell you how many volts are lost during the whole process. Set the Voltmeter to 10 VDC. 
6) Check all your connections and system otherwise, something could be wrong and ruin he whole experiment, the voltmeter, and the ammeter.
7) DO tables to record all your data since we are going to have four trials. One at its maximum current, one at 23 and the last one about 1/3.
8) DO all of these four trials and do not stay the circuit turned on because everything can come overheated and all the equipment could ruin so do it fast and accurately.
10) After you do all of these trials, do a graph and calculate the slopes for every trial.

Here is the data that I collected from the lab and here are the tables with all my results:

Maximum Voltage

Trial Current ± 0.05 Voltage ±0.05
0 0 0
1 0.4 4.2
2 0.6 6.8
3 0.9 9.6
4 1.1 11.4
5 1.4 14.6

2/3 Voltage

Trial Current ± 0.05 Voltage ±0.05
6 1.9 12
5 1.7 10.7
4 1.3 8.2
3 1 6.4
2 0.7 4.5
1 0.4 2.4
0 0 0

1/3 Voltage 

Trial Current ± 0.05 Voltage ±0.05
8 3.9 8.04
7 3.6 7.5
6 3.3 6.88
5 3 6.32
4 2.5 5.3
3 2 4.31
2 1 2.23
1 0.5 1.15
0 0 0

Bulb Voltage

Trial current ± 0.05 Voltage ± 0.05
0 1.8 10.45
1 1.4 6.2
2 1 3.6
3 0.6 1.41
4 0.2 0.4
5 0 0

Here is all the data that I got from the whole lab. In this next part of the lab, I am going to have a graph showing the resistance of each of the voltages from the charts above. With this graph I'm going to try to find the slopes and try to prove and see which trial had the most resistance and why the graphs looks like that.

Conclusion

The first conclusion that we can make according the electrical resistance is that when it was at its maximum voltage it had a lower resistance and in the other hand, when you have less voltage you have more resistance. When the breadboard was set to maximum voltage, the resistance was very low because electrons crash less times and the electrons take more time to go around a whole phases so that is what makes the higher voltage to have a lower resistance.

You can also prove this by using the formula V=IR. The one who had an intermediate resistance was the 2/3 voltage which was in the middle between 1/3 and maximum voltage. In the part where we had the maximum resistance was in 1/3 voltage. Electrons take shorter time to go around the breadboard that what causes the electrons to crash faster and because there is too much crushing, the ammeter starts to get warmer because there is too much friction and energy loss from the electrons.

That energy goes to heat, that why the equipment started burning out because of this friction. We can also see the bulb's graph, which starts at very little and then grows up quickly. The graph looks like an exponential graph, which is indeed, what the bulb was doing. It was almost increasing double as you raised up the voltage in the breadboard. I can make those conclusions from the graph that I have.

When I looked at the data tables, they seemed to be correct until Mr. Horn said that it was wrong because the ammeter was not going at a constant range so we had to do the first part again but it was no problem. You can see there is a lot of deviation in the tables. That was because the volt and the ammeter did not stayed constant so we calculated an estimate for all numbers and we came up with this number 0.05, which really worked out great.

We could had done this lab better is we had an accurate equipment because at the beginning we had to change station because the power supply was not working. The ammeter and the voltmeter were not working well because they could not stay still, it was always jumping like from 1.53 to 1.58 and then to 2.49 so we could not read an exact measurement. I think that other than that, we did a good lab.