# mirror

Topics: Eye, Optics, Mirror Pages: 3 (593 words) Published: March 2, 2014
﻿MIRROR
-The simplest and the most common optical instrument.
-Uses the Law of Reflection to redirect light it receives.
-It reflects most of the light in one direction.
-Good reflecting mirrors can have 85% reflectance.
Types of Mirror
1. Plane Mirror
A mirror with a flat surface.
Image formed:
Laterally inverted
Upright and always the same size as the object they reflect. Virtual image (images appear to behind the mirror) at the same distance as the object in front of the mirror. Examples: Mirrors used at home, bedroom, dressing room or bathroom 2. Spherical Mirror/ Curve Mirror

A spherical mirror has
a. Center of curvature C – the center of the sphere that the mirror is part of b. Focal point or Focus F – is the point where parallel light rays converge or apparently diverge upon reflecting off the surface of the mirror. c. Principal axis – is the line that contains the center of curvature, the focus, and the center of the mirror. Types of Curve Mirror

a. Concave Mirror
Curves inward like the inside surface of a hollow sphere
It is described as converging mirror
Image formed depends on the location of object. It can be real (when light rays meet at a pint) or virtual, reduced, or enlarged, and upright or inverted. Examples: mirrors used in flashlights, searchlights, and headlights b. Convex Mirror

Curves like the surface of the ball as seen from outside.
It is describe as diverging mirror
Image formed is virtual, reduced, and upright
Examples: rearview mirror and mirror used on banks and stores Mirror Equation
It describe the relationship between the distance of the object, dO , the distance of its images, di , and the focal length, f, of a spherical mirror. In symbols:

+ =

LENSES
One of the most useful and simplest optical devices we have. Types of Lenses:
a. Concave Lens – The rays are diverged by the lens, thus calling it a diverging lens
b. Convex Lens – are designed so that parallel rays cross at the...