A physics team must determine the focal length of a convex security mirror mounted in…
PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A physics team must determine the focal length of a convex security mirror mounted in a hallway. Because the mirror forms only virtual images, the standard screen-based method cannot be used.
(a) Describe how the principle of parallax can be employed to locate the apparent position of a virtual image produced by the mirror.
(b) Outline a detailed experimental procedure—using only a meterstick, a distant reference object, and three different object positions—to obtain numerical values of the object and image distances needed for calculating the focal length.
(c) Discuss the sign conventions that must be applied to object distance, image distance, and focal length for a convex mirror, and explain the physical meaning of a negative focal length in this context.