resistance of a wire

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Aim: To investigate how changing the length of the wire affects its resistance. What is resistance? Electricity passes through a material which is a conductor. In this experiment I will be using a wire. A better conductor is a material which has a lot of free electrons. For example silver has more free electrons than iron and therefore is a better conductor. The electrons are given energy and begin to move and collide with neighboring free electrons. This happens across the length of the wire and electricity is conducted. Resistance involves the collisions between the free electrons and fixed particles of the metal. These collisions convert some energy that the free electrons are carrying into heat. Factors: Factors are things which will affect the experiment. There are many factors to consider during this experiment; below I have compiled a list of these factors: The cross-sectional area – The cross-sectional area is the diameter of the wire the thickness of the wire. Cross-sectional area measures from one side straight to the other side. Resistance decreases as the diameter of the wire increases. The resistance of the wire decreases because there is more space for the electrons to move. In comparison resistance increases as the diameter of the wire decreases because there is less space for the electrons to move around in, they are compacted. This shows that cross-sectional area has to be taken into consideration when trying to find out weather the length of a wire affects resistance. Length - The length of the wire is another factor which affects the resistance. Length and resistance are always in proportion, as one increase so does the other they both increase by the same amount. This means that if the length of the wire was to increase the resistance would increase as. This rule also applies if you were to decrease the length of the wire

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