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Investigation to show if constantan is a suitable replacement for copper wire Electricity is the flow of electrons within a circuit. In current electricity negative charges are made. Resistance is anything, which hinders the movement of these electrons. The definition of resistivity is the ability, measured in ohm metres, of a cubic metre of material to oppose the flow of an electric current. (Symbol rho-r). Resistance occurs because of the particles in the material of the wire/conductor and how the material moves around them. E.g. Low resistance In thicker wire the particles are a lot more spaced out so it is easier for the electric current to move around the particles-if the particles collided Ek is transferred to the particles causing an increases in heat. High resistance In thinner wire the particles are a lot closer together so that the movement of the current is hindered. Other factors that may affect the resistance are; · The physical dimensions of the wire, long wires have more resistance than shorter wires, so the longer the sample of material, the greater the resistance. · Doubling the Cross Sectional Area of the wire also doubles the number of charge carriers there are to carry the current