The Factors Affecting the Resistance of a Wire
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Introduction
THE FACTORS AFFECTING THE RESISTANCE OF A WIRE By Ali Allana 4J2 (4A2) Mr. Kerr THEORY What is resistance? As free electrons move through a metal due to an applied potential difference they collide with each other and with the atoms of the metal crystal lattice. The property of the material that restricts this movement is known as the resistance of the conductor. Ohm's Law and resistance Connect a single cell with a 6V lamp and a suitable ammeter. Note Ammeter readings as you increase the p.d using extra cells. Increase the p.d across the ends of a conductor and a greater current flows. ...read more.
Middle
5. Pressure 2. Temperature 6. Dimension (coiled) 3. Length 7. Magnetic Field 4. Thickness Key Variables that affect the resistance of a wire 1. Temperature 2. Material 3. Wire length 4. Wire width Prediction Temperature If the wire is heated up the atoms in the wire will start to vibrate because of increase in energy. This causes more collisions between the electrons and the atoms as the atoms are moving into the path of the electrons. Increase in collisions means that there will be an increase in resistance. Material: The type of material will affect the amount of free electrons that are able to flow the wire. ...read more.
Conclusion
Wire length: If the length of the wire is increased then the resistance will also increase as the electrons will have a longer distance to travel and so more collisions will occur. Due to this the length increase should be proportional to the resistance increase. Wire width: If the wires width is increased the resistance will decrease. This is because of the increase in the space for the electrons to travel through. Due to this increased space between the electrons there will be less collisions and the resistance will decrease. Preliminary work We will do extensive research on which width of wire is available in different materials in order to find the materials that will give us the best possible results. 1 ...read more.
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