---
title: "A long, tightly wound cylindrical solenoid carries a constant current \\(I\\). In the ideal solenoid approximation, what are the characteristics of the magnetic field in the interior region far from the ends and in the exterior region immediately outside the solenoid?"
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url: "https://nerd-notes.com/ubq/121218/"
date_modified: "2026-08-23T04:58:55+00:00"
---

# A long, tightly wound cylindrical solenoid carries a constant current \(I\). In the ideal solenoid approximation, what are the characteristics of the magnetic field in the interior region far from the ends and in the exterior region immediately outside the solenoid?

A long, tightly wound cylindrical solenoid carries a constant current \(I\). In the ideal solenoid approximation, what are the characteristics of the magnetic field in the interior region far from the ends and in the exterior region immediately outside the solenoid?

![A horizontal cylindrical solenoid drawn with evenly spaced circular wire loops along its length. A dashed horizontal line runs along the central axis of the cylinder. A curved arrow at the left end of the winding indicates current \(I\) circulating through the coils. Text label 'Interior' is located inside the central region of the cylinder. Text label 'Exterior' is located outside above the top edge of the cylinder. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-solenoid-1-1787461135-wfBrBI.jpg)

- **A.** Interior: Nonuniform and nonzero | Exterior: Nonzero
- **B.** Interior: Nonuniform and nonzero | Exterior: Zero
- **C.** Interior: Uniform and nonzero | Exterior: Nonzero
- **D.** Interior: Uniform and nonzero | Exterior: Zero

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/121218/*