---
title: "A singly charged positive ion with charge \\(q = 1.6 \\times 10^{-19}\\text{ C}\\) and mass \\(m = 3.2 \\times 10^{-26}\\text{ kg}\\) enters a region of uniform magnetic field of magnitude \\(B = 0.50\\text{ T}\\). The ion travels with a speed of \\(v = 4.0 \\times 10^5\\text{ m/s}\\) perpendicular to the magnetic field and undergoes uniform circular motion. What is the radius of the circular path traversed by the ion?"
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url: "https://nerd-notes.com/ubq/121226/"
date_modified: "2026-08-23T04:58:56+00:00"
---

# A singly charged positive ion with charge \(q = 1.6 \times 10^{-19}\text{ C}\) and mass \(m = 3.2 \times 10^{-26}\text{ kg}\) enters a region of uniform magnetic field of magnitude \(B = 0.50\text{ T}\). The ion travels with a speed of \(v = 4.0 \times 10^5\text{ m/s}\) perpendicular to the magnetic field and undergoes uniform circular motion. What is the radius of the circular path traversed by the ion?

A singly charged positive ion with charge \(q = 1.6 \times 10^{-19}\text{ C}\) and mass \(m = 3.2 \times 10^{-26}\text{ kg}\) enters a region of uniform magnetic field of magnitude \(B = 0.50\text{ T}\). The ion travels with a speed of \(v = 4.0 \times 10^5\text{ m/s}\) perpendicular to the magnetic field and undergoes uniform circular motion. What is the radius of the circular path traversed by the ion?

![A rectangular region containing a grid of four rows of five crosses representing a uniform magnetic field into the page, labeled B = 0.50 T in the upper right. To the left of the rectangle, a small solid circle labeled +q with mass m has a horizontal arrow pointing to the right labeled v entering perpendicularly into the magnetic field region. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787461136-dlJ601.jpg)

- **A.** \(0.040\text{ m}\)
- **B.** \(0.080\text{ m}\)
- **C.** \(0.16\text{ m}\)
- **D.** \(0.32\text{ m}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/121226/*