Wire Resistance Investigation

Wire Resistance Investigation

Planning

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Aim

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In this experiment the resistance change in a wire will be

investigated. I will be investigating if the thickness or

cross-sectional diameter of the wire affects the resistance.

Variables

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The input variable will be the thickness of the wire to the nearest

millimetre.

The output variable will be the readings on the ammeter and

voltmeters.

The controlled variables will be the length of wire and the current

being passed through the wire.

The length of wire will stay the same and will already be measured to

50cm for us. The current will be kept on the same level using the same

power pack.

Apparatus

Þ Power pack

Þ Banjo board

Þ Ammeter and Voltmeter

Þ Wires

Þ Bulb

Þ Wires to connect the apparatus

Þ Ruler

Þ Crocodile

Safety

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This is a very safe experiment as it does not involve any chemicals

however we must make sure the voltage does not go higher than 12V.

Diagram

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Banjo board

Method

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Þ Set up the apparatus as shown above.

Þ Measure a piece of wire to 50cm

Þ Clip on the crocodile clips at each end

Þ Turn the power pack to 12V

Þ Now write down the readings from the voltmeter and the ammeter

Þ Repeat with different thickness’ of wire

Þ Repeat the whole experiment 5 times so an average can be taken

Þ Work out the resistance (R=V/I)

Fair testing

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To keep my experiment a fair test I will bee using the same equipment

and making sure that the length of wire I use stay the same length. I

will also keep the power pack at 12V on all experiments

Prediction

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I think that when I increase the thickness of the wire, the resistance