Custom essays on Resistivity of Wire

The resistivity of wire is defined on the basis of the formula R=PL/A, where R stands for resistance, P stands for resistivity, L stands for the length of the wire, and A for cross-sectional area. In actuality, to prove the correctness of this formula, it is important to conduct experiments which can help to check the resistance and resistivity of the wire made of different materials. In fact, then study should focused on the empirical study of the resistivity of wire, which can help to define the resistivity of different types of wires and to prove the correctness of the formula. In this respect, it is important to lay emphasis on the fact that experiments should be the main method of the research conducted to prove the correctness of the formula and to reveal the actual interdependence between the resistivity, length and diameter of the wire.
In actuality, the formula R=PL/A, where R stands for resistance, P stands for resistivity, L stands for the length of the wire, and A for cross-sectional area implies that the resistivity of the wire depends on the length of the wire, resistance and the cross-sectional area. At the same time, it is important to lay emphasis on the fact that the material the wire is made of plays a very important role and influences both resistance and resistivity of the wire. At this point it is possible to refer to the Table 1 (See App.), which shows that the use of different materials can change the resistance and, therefore, resistivity of the wire. For instance, house wiring and high power wiring have different resistance and resistivity. However, at this point, why the difference in resistance and resistivity exists and what are the causes of this difference.
At this point, it is necessary to conduct several experiments. The first experiment involved the use of different materials, i.e. the same power was applied to different wires, which were made of different materials. Results of this experiment can be found in the Table 1 (App.). At the same time, the resistivity of the wire did not change, in spite of the difference of the material use. Instead, it is only the resistance that changed. Therefore, while answering the question why the resistivity varies, it is important to take into consideration other factors than the material the wire is made of because different materials have different resistance but the resistivity does not different as a rule. At any rate, in the course of the experiment such differences were not found.
At the same time, it would be logical to presuppose that the length and diameter of the wire can also affect the resistance and resistivity of the wire. On the other hand, the length and diameter of the wire are crucial for the formula R=PL/A, where R stands for resistance, P stands for resistivity, L stands for the length of the wire, and A for cross-sectional area. To prove the correctness of the formula, it is necessary to prove that the length and diameter of the wire does matter for the resistivity and resistance of the wire. To meet this goal two experiments were conducted. First, the length of the wire changed and the resistivity measures. In the result of this experiment, the change in the resistivity was found out. In fact, the resistivity increased proportionally to the length of the wire. One more experiment used in the course of the study focused on the use of the wire of a different diameter. The change of the diameter revealed the change of the resistivity. To put it more precisely, the wire with the greater diameter had the smaller resistivity. Therefore, the increase of the diameter leads to the decrease of the resistivity.
Thus, taking into account all above mentioned, it is important to lay emphasis on the fact that empirical experiments prove the correctness of the formula R=PL/A, where R stands for resistance, P stands for resistivity, L stands for the length of the wire, and A for cross-sectional area. To put it more precisely, the change of the length and the diameter of the wire leads to the change of the resistivity.

References
Hooks, L. (2007). Resistance and Resistivity. New York: Routledge.
Resistance of Wire. 2010. Retrieved on July 11, 2010
Seymour J. (1972). Physical Electronics. New York: Pitman.
Ward, M.R. (2008). Electrical Engineering Science. Chicago: Touchstone.