In this experiment designed for use with PASCO Capstone software, discover the relationship between the resistance of a wire and its length, diameter, and the resistivity of the metal.
The current is measured directly by the Power Amplifier, and the voltage drop over the selected section of wire is measure by the Voltage Sensor. This allows easy calculation of the resistance of the length of wire. The resistance is plotted versus the length of the wire, and the slope of the resulting straight line is used to determine the resistivity.
Using wires of the same diameter made of different materials allows examination of the effect of resistivity. Using brass wires with various diameters allows examination of the effect diameter has on resistance.
The Resistance Apparatus has a slide-wire probe to easily change the measured length of the wire, and utilizes a four-wire hook-up to accurately measure the voltage drop.
The 850 Universal Interface Power Amplifier makes it possible to scan the voltages, allowing more time to examine wires made of different metals and having different diameters.