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GCSE Physics Coursework - Resistance of a Wire CourseworkResistance of a WireTaskTo investigate how the resistance of a wire is unnatural by the distance of the wire.TheoryWhat is resistance?Electricity is conducted through a conductor, in this case wire, by means of stark electrons. The number of free electrons depends on the material and more free electrons means a break off conductor, i.e. it has less resistance. For example, gold has more free electrons than iron and, as a result, it is a better conductor. The free electrons are given energy and as a result move and collide with neighbouring free electrons. This happens across the length of the wire and thus electricity is conducted. Resistance is the result of energy freeing as heat. It involves collisions between the free electrons and the fixed particles of the metal, other free electrons and impurities. These collisions alter some of the energy that the free electrons are carrying into heat.How is it measured?The resis tance of a length of wire is calculated by measuring the current pay in the circuit (in series) and the voltage across the wire (in parallel). These measurements are accordingly applied to this formulaV = I R where V = Voltage, I = Current and R = ResistanceThis can be rearranged toR = VIOhms LawIt is alike relevant to know of Ohms Law, which states that the current through a metallic conductor (e.g. wire) at a constant temperature is proportional to the potential difference (voltage). Therefore V I is constant. This means that the resistance of a metallic conductor is constant providing that the temperature also remains constant. Furthermore, the resistance of a metal increases as its temperature increases. This is because at high temperatures, the particles of the conductor are moving around more quickly, thus change magnitude the likelihood of collisions with the free electrons.VariablesInputLength of wire. * Material of wire. Width of wire. scratch temperature of wire. O utput and thus the resistance of the wire. Voltage across wire. Current in circuit. Temperature of wire. The variable marked with a * will be varied, the other input signal variables will be kept constant. The output variable marked with a will be measured.PredictionsThe longer the wire, the higher the resistance. This is because the longer the wire, the more measure the free electrons will collide with other free electrons, the particles making up the metal, and any impurities in the metal.