How does the length of a nichrome wire affect the resistance in the circuit?

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How does the length of a nichrome wire

affect the resistance in the circuit?

Plan 

In this investigation I am going to find out how the length of a piece of nichrome wire affects the resistance in a circuit. The different variable I could look at include length, thickness, temperature, current and voltage. Testing to see how the length will affect the resistance I am going to set up a circuit and connect an ammeter and a certain length of wiring in series. I will then connect the voltmeter in parallel to the wire. When I turn on the power supply I will try and make the flow of current through the circuit last for just a few seconds and quickly take the readings on the ammeter and the voltmeter. This is because the wire is so thin when the current passes through it the wire melts and increases the resistance. Once the wire has cooled down I will turn on the power supply again (keeping the wire the same length) and re-take the readings on the ammeter and the voltmeter. I will do this for a third time and write down the readings. I will then cut the wire a certain length and repeat this again. For each different length of the wire I will take three readings to make sure I have correct results and that it is a fair test. I will not change any other variables apart from the length. I will start off with the wire being 1000 mm long and cut it down in 100 mm chunks so I take readings of each hundredth millimetre of the wire. The way that I will be able to work out whether the resistance increases or decreases I will use the formula:-

                Resistance (ohms) = Voltage (volts)

Current (amps)

        I predict that if you increase the length of wire then the resistance will also increase. This is because there is less space inside the wire to allow the current to pass through. The current is the number off electrons that pass through the circuit and the voltage is the push of the current. Changing the thickness of the wire helps if there is a very big current and a high voltage passing through a thin material, it will melt the wire if it is really thin. This is why power station have thick wires in their power pylons so they don’t melt from the high current and voltage.

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        I predict, as the wire increases in length so will the resistance because of the pressure of the electrons trying to get through the wire. As the wire increases in length the ability of the wire to stop melting will decrease because of the voltage in the circuit.

        To male the experiment a fair test I will repeat each test on the length of wire three time so that I can find an average of the resistance in the nichrome wire.  Ohm’s law states that for a fixed voltage applied to a different conductor there will be a different amount ...

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