---
title: "A thin, rigid wire carrying a constant current \\(I\\) lies in the xy-plane and is bent into a right angle at the origin. One semi-infinite segment extends along the positive x-axis from \\(x = 0\\) to \\(x = +\\infty\\) with current flowing away from the origin. A second semi-infinite segment extends along the negative y-axis from \\(y = -\\infty\\) to \\(y = 0\\) with current flowing toward the origin. Point \\(P\\) is located on the positive y-axis at coordinates \\((0, d)\\). Which of the following expressions represents the magnitude of the net magnetic field at point \\(P\\)?"
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url: "https://nerd-notes.com/ubq/118618/"
date_modified: "2026-08-04T08:12:00+00:00"
---

# A thin, rigid wire carrying a constant current \(I\) lies in the xy-plane and is bent into a right angle at the origin. One semi-infinite segment extends along the positive x-axis from \(x = 0\) to \(x = +\infty\) with current flowing away from the origin. A second semi-infinite segment extends along the negative y-axis from \(y = -\infty\) to \(y = 0\) with current flowing toward the origin. Point \(P\) is located on the positive y-axis at coordinates \((0, d)\). Which of the following expressions represents the magnitude of the net magnetic field at point \(P\)?

A thin, rigid wire carrying a constant current \(I\) lies in the xy-plane and is bent into a right angle at the origin. One semi-infinite segment extends along the positive x-axis from \(x = 0\) to \(x = +\infty\) with current flowing away from the origin. A second semi-infinite segment extends along the negative y-axis from \(y = -\infty\) to \(y = 0\) with current flowing toward the origin. Point \(P\) is located on the positive y-axis at coordinates \((0, d)\). Which of the following expressions represents the magnitude of the net magnetic field at point \(P\)?

![A Cartesian coordinate system in the xy-plane with black x and y axes. A thin wire carrying current I lies in the plane, consisting of two perpendicular semi-infinite segments meeting at the origin (0, 0). One segment extends along the negative y-axis from y = -3 to y = 0, with an arrowhead on the line pointing upward toward the origin, labeled I. The second segment extends along the positive x-axis from x = 0 to x = 3, with an arrowhead pointing to the right away from the origin, labeled I. A point labeled P is plotted on the positive y-axis at coordinates (0, d), marked with a small solid black dot at a distance d above the origin, with a dashed vertical dimension line of length d connecting (0, 0) to P. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785831120-Pv2q9F.jpg)

- **A.** \(\dfrac{\mu_0 I}{4\pi d}\)
- **B.** \(\dfrac{\mu_0 I}{2\pi d}\)
- **C.** \(\dfrac{\mu_0 I}{4\pi d}\sqrt{2}\)
- **D.** \(\dfrac{\mu_0 I}{4 d}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/118618/*