Investigating Resistances of Wires :: Papers

Investigating Resistances of Wires Aim To investigate different resistances of cables to see which has the most resistance and which shows the least resistance. I will be looking at resistances affected by the distance of wire. Variables I could change I had the choice of several variables to change such as length, cross sectional area, material and temperature the experiment is conducted at. Prediction I believe that by increasing the wires length it would increase the resistance. Therefor by decreasing the length it would also decrease the resistance. I also believe that the rate of the increasing resistance will be directly proportional to the length so if the length were doubled the resistance would also double. I think the graph will look like this Reason The property that transforms electrical energy into heat energy, in opposing electrical current, is resistance. A property of the atoms of all conductors is that they have free elec trons in the outer shell of their structure. As a result of the structure of all conductive atoms, the outer electrons are able to move about freely even in a solid. When there is a potential difference crosswise a conductive material all of the free electrons arrange themselves in lines moving in the comparable 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. (Information found on a GCSE Physics website) Ohms law In1826 Georg Ohm discovered that the current flowing through the wire is proportional to the potential difference crosswise it (providing the temperature stays the same.) Proportional means if you double the potential difference the current is doubled (this information was found in GCSE Physics for you text book ) Current through the wire IMAGE Amps Volts