---
title: "A student is asked to determine the resistivity \\( \\rho \\) of an unknown metal alloy. The student has a long spool of wire made of this alloy with a known uniform cross-sectional area \\( A = 2.0 \\times 10^{-7} \\text{ m}^2 \\). The student is provided with the following equipment: a variable DC power supply, a voltmeter, an ammeter, a meterstick, a switch, and several connecting wires with alligator clips."
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url: "https://nerd-notes.com/ubq/117712/"
date_modified: "2026-08-04T07:53:36+00:00"
---

# A student is asked to determine the resistivity \( \rho \) of an unknown metal alloy. The student has a long spool of wire made of this alloy with a known uniform cross-sectional area \( A = 2.0 \times 10^{-7} \text{ m}^2 \). The student is provided with the following equipment: a variable DC power supply, a voltmeter, an ammeter, a meterstick, a switch, and several connecting wires with alligator clips.

A student is asked to determine the resistivity \( \rho \) of an unknown metal alloy. The student has a long spool of wire made of this alloy with a known uniform cross-sectional area \( A = 2.0 \times 10^{-7} \text{ m}^2 \). The student is provided with the following equipment: a variable DC power supply, a voltmeter, an ammeter, a meterstick, a switch, and several connecting wires with alligator clips.

**Part a)** **Draw** a schematic diagram of a circuit that could be used to gather the necessary data to determine the resistance of different lengths of the wire. Use standard circuit symbols. **Label** the segment of the alloy wire being tested as a resistor \( R_{\text{wire}} \). *(2 points)*

**Part b)** **Describe** a procedure to collect the data required to determine the resistivity of the wire. Assume the circuit from part (a) has already been assembled. Include any steps necessary to reduce experimental error. *(2 points)*

**Part c)** The student follows the procedure and records the data in the table below. The student wants to determine the resistivity \( \rho \) of the wire by creating a linear graph. *(4 points)*

**Part d)** **Calculate** the experimental value of the resistivity \( \rho \) of the alloy using the slope of your best-fit line. *(2 points)*

**Part e)** During the experiment, the student leaves the switch closed for a long time during each trial, causing the wire to become noticeably warm. **Explain** how this temperature increase would affect the measured value of the current for a given potential difference. **Justify** whether the resulting calculated resistivity would be greater than, less than, or equal to the actual resistivity of the alloy at room temperature. *(2 points)*


*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/117712/*