Project cost ($):
1 hour to prepare, 1 hour for observation
May be obtained from hobby stores, hardware supply shops, home depot etc.
Be careful when handling electric cables and knives. Adult supervision recommended.
Table of Contents
This experiment was conducted to find out how temperature affects the conductivity and resistance of a wire. The experiment was done using copper wire of diameter 0.5 mm.
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.
The resistance of a conductor is a measurement of the opposition to the current flowing in it. The value of the resistance will increase as the length of the conductor is made longer and the resistance will reduce when the diameter of the conductor is increased. The value of resistance is measured in ohms.
Conductivity, resistance, current, ampere, voltage, volt, ohm
The materials required for this science fair project:
1. For this experiment, the independent variable is the temperature of the copper wire. The dependent variable is the resistance of the wire. This is determined by measuring the current and resistance of the wire. The constants (control variables) are the room temperature, the applied voltage, the diameter of the wire and the length of the wire.
4. The initial current reading shown on the ammeter is recorded in the table below. As the current flows in the magnet wire, the temperature of the wire will increase. This temperature is measured using the infrared thermometer. As the temperature increases 10°C, the ammeter reading is recorded, and the wire is disconnected from the circuit and the wire resistance is immediately measured using the ohm meter.
It is observed that as the temperature of the wire increases, the resistance of the wire also increases but the current flowing in the wire reduces.
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.
What would happen if the experiment was repeated using different wire sizes?
Electrical resistance - http://en.wikipedia.org/wiki/Electrical_resistance