---
title: "An optical pin is placed at various positive distances \\(d_o\\) along the principal axis of a concave spherical mirror with focal length \\(f\\). The corresponding image distance \\(d_i\\) is measured, where real images have \\(d_i > 0\\) and virtual images have \\(d_i  0\\)?"
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url: "https://nerd-notes.com/ubq/123301/"
date_modified: "2026-09-28T11:58:06+00:00"
---

# An optical pin is placed at various positive distances \(d_o\) along the principal axis of a concave spherical mirror with focal length \(f\). The corresponding image distance \(d_i\) is measured, where real images have \(d_i > 0\) and virtual images have \(d_i  0\)?

An optical pin is placed at various positive distances \(d_o\) along the principal axis of a concave spherical mirror with focal length \(f\). The corresponding image distance \(d_i\) is measured, where real images have \(d_i > 0\) and virtual images have \(d_i < 0\). Which of the following graphs best represents image distance \(d_i\) as a function of object distance \(d_o\) for all values of \(d_o > 0\)?

- **A.** Graph A
- **B.** Graph B
- **C.** Graph C
- **D.** Graph D

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123301/*