Does a hotter wire resist electricity more than a cool one? You wind 5 meters of thin copper wire around a PVC pipe and connect it to a 4.5 V battery pack. An ammeter measures the current and an ohm meter measures the resistance.
As current flows through the wire, its temperature rises. You use an infrared thermometer to track the temperature. Every time it climbs by 10 degrees Celsius, you record the current and resistance.
The data shows that resistance rises steadily as the wire heats up, while the current drops.
Hypothesis
The hypothesis is that when the temperature of a wire increases, the resistance value of the wire will also increase and therefore the conductivity of the wire will reduce.
A wire's temperature changes how easily current flows through it. You wind 5 meters of thin copper wire around a PVC pipe, connect it to a 4.5V battery pack, and track the current with an ammeter while an ohm meter measures resistance. As charged bits flow through the wire, the wire heats up. Every 10°C rise, you record both readings. The data tells a clear story: resistance climbs steadily as the wire gets hotter, and the ammeter shows the current dropping in response.
Temperature changes how much a material fights the flow of electric current. In this experiment, resistance rises steadily as the wire heats up, while the current drops. Hotter copper atoms vibrate more, making it harder for current to pass through the wire.
Method & Materials
You will wind a wire around a PVC pipe, measure the resistance of the wire, connect the wire to a battery, measure the current, and measure the temperature of the wire as it increases.
You will need a varnish insulated copper wire, a PVC pipe, three 1.5V batteries, jumper wires, an ohm meter, an ammeter, a paper knife, an infrared thermometer, and insulation tape.
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The experiment showed that as the temperature of the wire increases, the resistance of the wire also increases but the current flowing in the wire reduces. This confirms the hypothesis that when the temperature of a wire increases, the resistance value of the wire will also increase and the conductivity of the wire will reduce.
Why do this project?
This science project is interesting because it shows how temperature affects the resistance of a wire and how it affects the flow of electricity.
Also Consider
Variations of this experiment could include repeating the experiment using different wire sizes or using aluminum wires.
Full project details
Additional information and source material for this project are available below.
