Day 11 Lab 04/07/14

Electric Circuits:

In this lab we were introduced to electric circuits and how each component works from the electric potential to the resistance of materials. We did experiments in which we found different relationships between different variables that give a better understanding why a light bulb lights up when just using a battery and one wire. Also in the lab we were able to see what resistance is and what affects the amount of resistance being applied because certain variables like length for example. Throughout this lab day we saw a circuit can be related to a stream and generator but also the physical definitions of words that we use like voltage and current.

This is the lab set up in which we attempted to light a bub by using the materials in the image and be able to create a close circuit to light it up.

The image shown is what we believe is being traveled through the wire where it is electrons moving from the positive to the negative side of the power supply. However in reality we said that it starts from the negative side and travel through the circuit giving it charge to be able to light the bulb.

After we saw the relationship using another situation we saw that the total power is just multiplying the voltage supplied and the current it gives of as it travels from one point to the other and recycling the electrons.



This another image of the experiment but this time we used equipment that made it easier to make a circuit without using actual hands.

In order to prove the movement inside the current and see the interaction within that wire we needed to place a voltammeter in the circuit to read the amount of amps is in the circuit. After doing the experiment we saw that the current was the same when the voltammeter was moved from one side to the other proving it was the same. We can also use the voltammeter to record the other values in the circuit.

This is the lab setup in which we were able to record the current by placing it in the circuit because it has to be a closed circuit in order to see the current.

The part of the experiment we were given a resistor with a certain amount of coils tied around and we had to use a voltmeter and use it to find the resistance of the resistor. Then we compared values with another group to see the difference in the amount of resistance being applied. In this part of the lab we saw that both of the resistors were close to each other because we had the same amount of coils and similar length of the resistor. However we saw the difference between the other groups and saw there difference of the resistance.

This was the experiment setup in which we were able measure and record the circuit values needed to see the differences when we compared resistors to the other groups. With the voltmeter were able to measure the current, actual voltage and the use calculations to find the resistance.

This is the graph with the values of both groups to compare and see the see the relationship between the voltage and current to see that the relationship is linear  and directly proportional. V=IR.

The second part of the experiment was finding the relationship between the cross sectional area, length, and the material with the resistance. We were given different resistors each with different values in the components stated in the prior sentence and find how each one affects the resistance by using a voltmeter for resistance.

This the values of each resistor with the components stated above to come to a conclusion in the relationships between them and the resistance. At the bottom we can see the relationships of each component for example we saw that the resistance and the length where directly proportional to each other in a linear relationship. In the end came out with an equation incorporating all the values given here.

We used Excel program to make it easier by plugging in all the values and make the calculations less time consuming but the main thing was using the graphs to see the relationships between the cross sectional area, length and material with the resistance and be able to visualize the actual relationship between each one for example like in the image.