---
title: "A flat conducting ribbon of width \\(w\\), thickness \\(t\\), and charge carrier number density \\(n\\) carries a steady current \\(I\\). A uniform magnetic field of magnitude \\(B\\) is directed perpendicular to the flat face of the ribbon. A steady Hall potential difference \\(V_H\\) is measured across the width \\(w\\) of the ribbon. Assuming charge carriers each carry a charge of magnitude \\(e\\), which of the following expressions represents the current \\(I\\) in the ribbon?"
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url: "https://nerd-notes.com/ubq/118435/"
date_modified: "2026-08-04T08:10:04+00:00"
---

# A flat conducting ribbon of width \(w\), thickness \(t\), and charge carrier number density \(n\) carries a steady current \(I\). A uniform magnetic field of magnitude \(B\) is directed perpendicular to the flat face of the ribbon. A steady Hall potential difference \(V_H\) is measured across the width \(w\) of the ribbon. Assuming charge carriers each carry a charge of magnitude \(e\), which of the following expressions represents the current \(I\) in the ribbon?

A flat conducting ribbon of width \(w\), thickness \(t\), and charge carrier number density \(n\) carries a steady current \(I\). A uniform magnetic field of magnitude \(B\) is directed perpendicular to the flat face of the ribbon. A steady Hall potential difference \(V_H\) is measured across the width \(w\) of the ribbon. Assuming charge carriers each carry a charge of magnitude \(e\), which of the following expressions represents the current \(I\) in the ribbon?

![A three-dimensional perspective view of a rectangular conducting ribbon aligned horizontally. The ribbon has length along the x-axis, width \(w\) along the y-axis, and thickness \(t\) vertically along the z-axis, with \(t\) noticeably smaller than \(w\). A bold arrow labeled \(I\) points to the right along the length of the ribbon. A uniform magnetic field is represented by three vertical parallel arrows pointing upward through the flat top surface of the ribbon, each labeled \(B\). Across the transverse width \(w\) on the top face, two small terminal dots are shown on opposite long edges, connected by dashed leads to a voltmeter symbol labeled \(V_H\). A dimension line across the top face marks the width \(w\), and a dimension line on the front vertical edge marks the thickness \(t\). No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785831003-tfrRok.jpg)

- **A.** \( \dfrac{n e t V_H}{B} \)
- **B.** \( \dfrac{n e w V_H}{B} \)
- **C.** \( \dfrac{n e t^2 V_H}{B w} \)
- **D.** \( \dfrac{n e w^2 V_H}{B t} \)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/118435/*