Copper Wire Resistivity
Problem
Does temperature affect the resistivity of different sized copper wires?
Hypothesis
I think that the resistivity will increase with higher temperatures because with higher temperature, resistivity is higher due to the fact the atomic lattice structure increases.
Background Electrical resistivity is the measurement of how a material opposes the flow of an electrical current. On the other hand, electrical conductivity () is the inverse of resistivity. It is the measurement of how a material accommodates to electrical currents. If temperature changes, the resistivity and conductivity will change accordingly. Temperature coefficient of resistivity () is a measure how temperature affects resistivity. We cannot measure resistivity directly- however by measuring the resistance of a wire with an ohmmeter, we can calculate the resistivity.
Materials * Multimeter/Ohmmeter * Enamel-Coated Magnet Copper Wires (30-gauge, 34-gauge) * Thermometer * Solder and Rosin * Iron * Portable Refrigerator/Heater * Alligator Clips * 2 wires pairs (of same size)
Procedure 1. Gather materials 2. Connect copper wires to the 2 pairs of wires, then onto the alligator clips 3.1. With parent supervision, get solder and rosin on the tips of the wires and iron them together (one pair to each roll of wires) 3.2. Connect the wire to the alligator clips, once again using the solder and rosin. 3. With the ohmmeter at a range of 200 ohms, measure all 2 wires at a stable room temperature 4. Measure the two wires with an altered temperature 5.3. Using a portable refrigerator, set it to cold to lower the temperature 5.4. At a stable low temperature, measure the 2 wires with the ohmmeter 5.5. Repeat 4.1 and 4.2 with heat 5. Use the formula = RA/L (where =resistivity, R=resistance, A=cross-section area, L=Length) to find resistivity based on data
Data Tables
Wire
Does temperature affect the resistivity of different sized copper wires?
Hypothesis
I think that the resistivity will increase with higher temperatures because with higher temperature, resistivity is higher due to the fact the atomic lattice structure increases.
Background Electrical resistivity is the measurement of how a material opposes the flow of an electrical current. On the other hand, electrical conductivity () is the inverse of resistivity. It is the measurement of how a material accommodates to electrical currents. If temperature changes, the resistivity and conductivity will change accordingly. Temperature coefficient of resistivity () is a measure how temperature affects resistivity. We cannot measure resistivity directly- however by measuring the resistance of a wire with an ohmmeter, we can calculate the resistivity.
Materials * Multimeter/Ohmmeter * Enamel-Coated Magnet Copper Wires (30-gauge, 34-gauge) * Thermometer * Solder and Rosin * Iron * Portable Refrigerator/Heater * Alligator Clips * 2 wires pairs (of same size)
Procedure 1. Gather materials 2. Connect copper wires to the 2 pairs of wires, then onto the alligator clips 3.1. With parent supervision, get solder and rosin on the tips of the wires and iron them together (one pair to each roll of wires) 3.2. Connect the wire to the alligator clips, once again using the solder and rosin. 3. With the ohmmeter at a range of 200 ohms, measure all 2 wires at a stable room temperature 4. Measure the two wires with an altered temperature 5.3. Using a portable refrigerator, set it to cold to lower the temperature 5.4. At a stable low temperature, measure the 2 wires with the ohmmeter 5.5. Repeat 4.1 and 4.2 with heat 5. Use the formula = RA/L (where =resistivity, R=resistance, A=cross-section area, L=Length) to find resistivity based on data
Data Tables
Wire