Investigate how the electrical resistance of a wire changes in relation to its length.

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Gabriella Blake AIM: TO INVESTIGATE HOW THE ELECTRICAL RESISTANCE OF A WIRE CHANGES IN RELATION TO ITS LENGTH PLAN Introduction and background research ·     Resistance can be found using the equation Resistance = voltage current ·     It is measured in Ohms (Ώ) ·     Ohms Law states that the current (I) through a conductor is directly proportional to the voltage (V) across the conductor and inversely proportional to its resistance. ·     The resistance of a wire is effected by: - Ø     Length Ø     Diameter Ø     Temperature Ø     Type of metal Ø     Cross-sectional area ·     In a conductor, some electrons break away from the atoms. These electrons move freely inside the conductor. When there is a voltage across a conductor, all of the free electrons arrange themselves in lines moving in the same direction. This forms an electrical current. Resistance is come across when the charged particles that make up the current collide with other fixed particles in the material. As the length of wire is increased, the number of collisions the current carrying charged particles makes increases and, therefore, the value for the resistance of the wire becomes higher. ·     In 1826, Georg Ohm discovered that the current flowing through metal wire is proportional to the potential difference across it (providing the temperature remains constant.) Georg Simon Ohm 1787-1854 ·     An electric current is the flow of electrons (tiny negative particles), which flow from the negative end of the battery, they travel around the wire and arrive back at the positive end. ·     Potential difference is measured in volts (V), current is measured in amps (A). ·     Resistance is a measurement describing the difficulty of electric current flowing a conductor. ·     In metals, the outermost electrons are held only very weakly to the atom and often wander away from it and go to the nearby atom or one a bit further away. These wandering electrons are called conduction electrons and the more of these there are, for a given volume of metal, the better the metal will be as a conductor of electricity. When you connect a battery across a wire, one end becomes positive and attracts the conduction electrons, which drift towards that end of the wire. But the electrons have obstacles to face because the metal atoms are moving about because of their thermal energy and so the electrons collide with them and are knocked everywhere. It’s this difficulty that the electrons have in moving along the wire that we call resistance.
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·     The higher the resistance, the lower the current. If there is high resistance, to get the same current a higher voltage will be needed to provide an extra push for the electricity. ·     Resistance opposes the flow of an electric current around a circuit so that energy is required to push the charged particles around the circuit. The circuit itself can resist the flow of particles if the wires are either very thin or very long. Prediction When the length of wire increases so does the resistance. The rate the resistance of the wire increases will be directly proportional ...

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