Resistance Of Wire :: Papers

Resistance Of Wire Aim. To find out what happens to the resistance of a wire, when you change the length of the wire. Background Information. A current of electricity is the be given of negatively charged electrons around a circuit. IMAGE IMAGEIMAGE IMAGE IMAGE IMAGE IMAGE Close up, the wire and the electrons look like this IMAGE The electrons collide with the atoms as they travel through. We say the atoms oppose the flow of electrons. This is called resistance, and the wire gets hotter. In 1826, Georg Ohm discovered that when a current flows through a metal wire the current and the potential differences are proportional, providing that the temperature remains constant. The resistance of wire can be calculated using IMAGE Variables. Temperatureincreases the resistance as the atoms are getting hotter they are vibrating and moving faster. This makes the atoms and the electrons collide more. Thickness of wire decreases the resistance , as there is more path for the electrons to travel past the atoms. They dont collide as much. Length of wire increases the resistance because the electrons encounter further to move and more collisions occur. So, if you double the length of wire, you double the resistance. Because the get along of atoms and the number of collisions doubles. Type of wireaffects resistance because different qualitys have different atom arrangements. Some have different patterns, and some are arranged so that electrons have an easier path to travel through the atoms. Fair Test. To make the experiment fair, I will make sure that the temperature stays the same flowing through the index number pack and wire. I will do this by turning it off and recording my results quickly. In addition, I will make sure that the thickness and the type of wire are the same. I will only change the length of the wire. Prediction. I predict that the resistance will increase because the le ngth of wire