---
title: "A thin wire is bent into a circular arc of radius \\(R\\) that subtends an angle \\(\\theta\\) (measured in radians) and carries a steady current \\(I\\), as shown. Which of the following expressions correctly gives the magnitude of the magnetic field \\(B\\) produced by the arc at its center of curvature \\(P\\)?"
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url: "https://nerd-notes.com/ubq/118507/"
date_modified: "2026-08-04T08:11:10+00:00"
---

# A thin wire is bent into a circular arc of radius \(R\) that subtends an angle \(\theta\) (measured in radians) and carries a steady current \(I\), as shown. Which of the following expressions correctly gives the magnitude of the magnetic field \(B\) produced by the arc at its center of curvature \(P\)?

A thin wire is bent into a circular arc of radius \(R\) that subtends an angle \(\theta\) (measured in radians) and carries a steady current \(I\), as shown. Which of the following expressions correctly gives the magnitude of the magnetic field \(B\) produced by the arc at its center of curvature \(P\)?

![A single circular arc of radius R subtends an angle \theta at its center of curvature, labeled P. An arrow along the arc indicates a current I flowing counterclockwise. A dashed radius line connects center P to one end of the arc, and another dashed radius line connects center P to the other end, with the angle between them labeled \theta. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785831070-XovOmO.jpg)

- **A.** \(\dfrac{\mu_0 I \theta}{4\pi R}\)
- **B.** \(\dfrac{\mu_0 I \theta}{2\pi R}\)
- **C.** \(\dfrac{\mu_0 I}{4\pi R \theta}\)
- **D.** \(\dfrac{\mu_0 I \theta^2}{4\pi R}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/118507/*