Therefore my predictions was correct because as I changed the material (copper, constantan and Nichrome had different readings on the ammeter, this is because different materials hold there electron tightly or not tightly. In my prediction early on I said that: As I change the materials (Copper, Constantan and Nichrome) different readings from the ammeter and voltage will occur, and I expected that copper will have the least resistance of the three materials, followed by constantan, and then nichrome.
In other words I expect copper to be the highest conducting material, and nichrome the lowest conducting material, while constantan ranks second to copper. The reason is that copper allows more current to flow because it does not hold the electrons very hard compared to constantan and nichrome which are alloys that hang on to their electrons more tightly and therefore tend to have high resistance to electrical current. The following electron distribution shapes give qualitative ideas as to why copper has highest conductivity (and least resistance), and nichrome the lowest conductivity (and highest resistance) of the three materials Constantan.
The reason why constantan does not allow current to pass throw is because constantan hold the electron very hard and makes it more difficult for the current to flow through the mental, also gives lots of energy is released. Nichrome The reason why Nichrome does not allow current to pass throw is because nichrome hold the electron very hard and makes it more difficult for the current to flow through the mental, also gives lots of energy is released. . Copper The reason why copper allow current to pass throw is because copper does not hold the electron very hard as nichrome and constantan and so is allows more current, and also releases energy.
Also I predict Copper allows more current because copper does not hold on to their electrons very hard as nichrome and constantan, which eventually allows more current to pass through, and also releases energy. We say copper is a good conductor of electricity or a low resistance to electricity. On the other hand constantan and nichrome have high resistance to electricity compared to copper. They are used to reduce the current in the circuit. Constantan is an alloy used for general purposes. ; sometimes is called contra or eureka. Microbe is an alloy from which the elements of electric fires are made, since it resists oxidation when rod hot.
The resistance of constantan is about twenty-five times that of copper, and nichrome about sixty times that of copper. Table 1 below give the values of conductivity for the three materials. The conductivity is the inverse of resistively. Table 1: conductivity of some materials Material Conductivity, mhos/meter Copper 5. 7 ? 107 Constantan 2 ? 106 Nichrome 1 ? 106 So overall I do agree with my original prediction ,which I made early on Graph B I have noticed a pattern in graph B, as the length of the wire increases the resistance increased as well. This shows that the length of the wire affects the resistance.
Suppose, for instances, that the length of a given wire is doubled. This doubles the resistance, since twice the length of wire is equivalent to two equal resistances in series. If the length of wire is increased five times the resistance likewise becomes five times its previous value, and so on. This is because as we increase the length of the length of the material, so does the resistance because increasing the mass or the number of protons inside the wire, so It has to overcome the larger number of particles of the wires, therefore, the resistance of the wire increases.
Early on in my prediction I stated that: The longer the wire the more resistance the material has to electrical current compared to the short wire. This is so because the longer the wire, means more material and particles are included in the face of electrical current which has to struggle more to overcome these particles. Also as the length of the wire is increased the number of collisions the current carrying charged particles make with fixed particles also increases and therefore the value for the resistance of the wire becomes higher. Resistance, in ohms (R) is also equal to the resistively of the wire.
Also in my prediction I stated that I believe that the rate at which the resistance of the wire increases will be directly proportional to the length, this is because structure of all conductive atoms, the outer electrons are able to move about freely even in a solid. When there is a potential difference across a conductive material all of the free electrons arrange themselves in lines moving in the same direction. This forms an electrical current. Resistance is encountered when the charged particles that make up the current collide with other fixed particles in the material.
As the resistance of a material increases so to must the force required to drive the same amount of current Electric current is the movement of electrons through a conductor. In this experiment a metal wire (Copper, Constantan and Nichrome will be the conductor). So when resistance is high, conductivity is low. Metals such as Copper, Constantan and Nichrome conduct electricity well because the atoms in them do not hold on to their electrons very well. Free electrons are created, which carry a negative charge, to jumps along the lines of atoms in a wire, which are in a lattice structure.
Resistance is when these electrons, which flow towards the positive, collide with other atoms; they transfer some of their kinetic energy. This transfer on collision is what causes resistance. So, if we double the length of a wire, the number of atoms in the wire doubles. This increases the number of collisions and energy transferred twice, so twice the amount of energy is required. This means the resistance is doubled. Also I stated that In circuits containing metallic conductors, the only particles that are free to move are electrons.
Metals contain positive ions, neutral atoms that have lost one or two of their outermost electrons. Theses electrons are free to move about in the mental and are affected by electric forces. Any movement of charges is an electric current. I think that from my results I can safely say that my prediction was right. The resistance did change in proportion to the length. This is because as the length of the wire increased the electrons that made up the current, had to travel through more of the fixed particles in the wire causing more collisions and therefore a higher resistance.
We can work out what the resistively of the wire should be from our results using the formula. Evaluation I completed my experiment successfully because I have good results. My aim was to find out which material affected the resistance the most. I did find what I was looking for, which was that copper allows the most current through . I could have made my results more reliable by repeating it or checking it two times. I think that I did have enough measurement because I repeated my experiment 3 times and I also covered ever angle in my investigation .
I think that I should not have taken an wider results because I have recorded all my results. I could have made my results more accurate by getting the same person to read the ammeter and the voltage. I could have not made my method more accurate because, I planned everything ahead . The equipment that I used to measure the current was a ammeter and for the push of the current I used an voltmeter. My repeated results were similar to my original ones. I did count the amount of current that flows through the materials.
There was not one result that did not fit my pattern. All my results where as I expected to be for e. g. I expected copper to allow more current to flow in because it was not holding its electrons tightly. If I were to do my experiment again, I would try to improve it by collecting more research and to improve my concentration on that topic. If I were to do a different experiment on the same topic, I would do the length of wire that which the resistance. The other experiment that I could have done was the length of wire, which affected the resistance the most.
The other variable that I could have tested if I was to do another experiment on the same topic where the measurement of the diameter of the wire e. g. 30cm, 32cm, 38cm I could have tested. Also the other variables that I could have tested were the length of the wire for e. g. 10 cm, 20cm, 30cm, 40cm and so on. In the Analysis and the graph I have shown one main anomalous point, this means that there must have been a slight error in my experiment. As the wire, length is bigger at these points I found it harder to stretch it out and consequently, measure it accurately.
Although the graph is overall accurate and the results precise it is easy to see, the anomalous averages plotted because they do not all lie along the same best-fit line. The graph shows that my results are reliable as there are only one main anomalous points, (which are easily accounted for) to improve the reliability of my results, I could do more repeats in doing this my average would be more reliable. As I increased the wire length, the wire became hotter and gave off heat. This could explain why the anomalous results are at the top of my graph, 90cm
I have noticed several modifications I could make to improve on the Investigation if I was to repeat it. The first of these modifications would be the circuit that I would use. To be more accurate with my results I would place the Metre rule directly under the wire, so therefore it would be measured easier and therefore making the lengths more precise. Instead of connecting the voltmeter to the main circuit, I would connect it to the wire that is being tested. I would do this so that the voltmeter is measuring the voltage of just the wire being tested and not the wires of the main circuit as well.
To also improve on my results I could use a new or higher quality digital voltmeter. The next modification I would make would be to use pointers instead of crocodile clips to attach to the wire; I would do this because pointers would be more accurate. The pointers would be more accurate because the tips have a much smaller area than the crocodile clips giving a more accurate measurement of the length of wire. I would also use a newer metre rule. The graph shows that my results are reliable as there are only two anomalous points, to improve the reliability of my results, I could also have repeated the same lengths of wire more times.