A mirror designer compares three mirrors that share the same diameter: a plane mirror
PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A mirror designer compares three mirrors that share the same diameter: a plane mirror, a concave spherical mirror, and a convex spherical mirror. In each case, parallel rays of light arrive along a common principal axis toward the reflective surface. The designer wants to understand how the curvature of the reflective surface influences where an image forms and how that image appears to an observer.
(1) Describe qualitatively how the sign of the mirror's curvature (concave versus convex) determines whether the reflected rays appear to originate from a point in front of the mirror or behind it.
(2) Explain why the location of the focal point moves farther from the mirror surface as the magnitude of the mirror's radius of curvature increases.
(3) Using a limiting argument that treats the plane mirror as the case in which the radius of curvature grows without bound, explain why the image produced by a plane mirror always appears the same distance behind the mirror as the object is in front.