Question

A student is given three wires that are made from different materials, but each wire has the same physical dimensions. For a given experiment, both ends of one wire are connected to a constant voltage power supply so that a closed circuit is established. The student has access to an ammeter and a voltmeter to make measurements for each wire. Which of the following types of data need to be collected to rank the wires in terms of their resistivity. Justify your selection. Use the ammeter to measure the current that flows through each wire, because a larger current that flows through the wire corresponds to a larger resistivity. Use the ammeter to measure the current that flows through each wire, because a larger current that flows through the wire corresponds to a smaller resistivity. Use the voltmeter to measure the potential difference across the wire, because a larger potential difference corresponds to a larger resistivity. Use the voltmeter to measure the potential difference across the wire, because a larger potential difference corresponds to a larger resistivity.

Answer 1

Use the ammeter to measure the current that flows through each wire, because a larger current that flows through the wire corresponds to a smaller resistivity

Step-by-step explanation:

Since they are connected to a constant voltage power source, the potential difference does not change. The potential difference is proportional to the product of the current and the resistance and, the resistance opposes the flow of electric current. It is clear to see that a large current that flows through the current means there is a lesser resistance to the flow of current at constant potential difference across the circuit.