GCSE Physics Coursework
Resistance of a wire
Investigation
To find out how the resistance of a wire is affected by the length of the wire.
Metals conduct electricity because the atoms in the metals do not hold onto their electrons, and they create free electrons. The amount of free electrons depends on the material, and more free electrons means that a better a conductor it will be, because it has less resistance. Silver would have more free electrons than iron so that makes it a better conductor. Resistance is made from energy, which is lost as heat. Collisions between the free electrons and the particles fixed in the wire change some of the energy into heat. Ohms law states that a current through a wire at the same temperature is proportional to the potential difference (the voltage). This means that the resistance of the wire conductor is the same if the temperature also stays the same. The resistance of a metal increases as its temperature increases, and this is because at higher temperatures, the particles of a wire are vibrating, faster, which increases the chances of them colliding with the free electrons.
Resistance of a wire
Investigation
To find out how the resistance of a wire is affected by the length of the wire.
Metals conduct electricity because the atoms in the metals do not hold onto their electrons, and they create free electrons. The amount of free electrons depends on the material, and more free electrons means that a better a conductor it will be, because it has less resistance. Silver would have more free electrons than iron so that makes it a better conductor. Resistance is made from energy, which is lost as heat. Collisions between the free electrons and the particles fixed in the wire change some of the energy into heat. Ohms law states that a current through a wire at the same temperature is proportional to the potential difference (the voltage). This means that the resistance of the wire conductor is the same if the temperature also stays the same. The resistance of a metal increases as its temperature increases, and this is because at higher temperatures, the particles of a wire are vibrating, faster, which increases the chances of them colliding with the free electrons.