---
title: "An object is placed at a distance \\(d_o\\) in front of a spherical mirror with focal length \\(f\\). According to the standard sign convention, \\(f > 0\\) for a concave mirror and \\(f < 0\\) for a convex mirror. Which of the following expressions correctly gives the lateral magnification \\(M\\) of the image purely as a function of \\(f\\) and \\(d_o\\)?"
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url: "https://nerd-notes.com/ubq/116857/"
date_modified: "2026-08-04T06:09:52+00:00"
---

# An object is placed at a distance \(d_o\) in front of a spherical mirror with focal length \(f\). According to the standard sign convention, \(f > 0\) for a concave mirror and \(f < 0\) for a convex mirror. Which of the following expressions correctly gives the lateral magnification \(M\) of the image purely as a function of \(f\) and \(d_o\)?

An object is placed at a distance \(d_o\) in front of a spherical mirror with focal length \(f\). According to the standard sign convention, \(f > 0\) for a concave mirror and \(f < 0\) for a convex mirror. Which of the following expressions correctly gives the lateral magnification \(M\) of the image purely as a function of \(f\) and \(d_o\)?

![A horizontal line represents the principal axis of a spherical mirror. A vertical curved arc on the right represents the spherical mirror, curving inward towards the left. A labeled point F on the principal axis marks the focal point at distance f from the mirror vertex. A vertical arrow pointing upward, labeled Object, stands on the principal axis to the left of F at an object distance d_o from the mirror. A horizontal dimension line below the axis indicates the distance d_o from the object to the mirror vertex. No rays, projected lines, or image arrows are shown. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785823792-JBYhBW.jpg)

- **A.** \(M = \dfrac{d_o - f}{f}\)
- **B.** \(M = \dfrac{f}{d_o - f}\)
- **C.** \(M = \dfrac{f}{f - d_o}\)
- **D.** \(M = \dfrac{d_o}{f - d_o}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/116857/*