# Effect of Temperature on the Conductivity and Resistance of a Copper Wire

Topics: Electric current, Volt, Ampere Pages: 3 (427 words) Published: February 8, 2012
Materials

5 meters of varnish insulated copper wire with diameter 0.5mm PVC pipe- 300mm length
3- 1.5 volt batteries with casing
3- jumper wires with crocodile clips
Multimeter
Scissors
Infrared Thermometer
1 roll of insulation tape

Procedure

1. Wind the wire around the PVC pipe. Fix the ends of the wires to the insulation tape. Remove about 3 cm. of insulation from the wire using the tips of the paper knife. Measure the resistance of the wire using the ohm setting on the multimeter. 2. Connect the batteries in series using the jumper wires to produce 4.5 V. The ammeter, battery and wire wound around the pipe should be connected as shown in figure 1.

3. Record the initial current reading shown on the ammeter. As the current flows in the magnet wire, the temperature of the wire will be increasing. Measure the temperature using the infrared thermometer. Record the ammeter reading as the temperature increases 10°C before disconnecting the wire from the circuit and measuring the wire resistance immediately using the ohm meter.

4. Repeat procedure 4 when the temperature of the wire increases every 10°C until the highest temperature is reached and the measurements are recorded. Conclusion
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 is proven to be true. The temperature of the wire increases due to its power loss, which is calculated as I2x R., where “I” is the current in the wire and R is the resistance. The higher the current in the wire or the higher resistance will cause the temperature of the wire to increase. Therefore it is important to choose the correct wire sizes to minimize this unwanted loss and reduce the temperature of the conductor. Observations

It is observed that as the temperature of the wire increases, the resistance of the wire also increases but the current flowing in the...