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Reflection of light
When the ray of light strikes a mirror, it reflects as shown in the figure below.
The incoming ray is the incident ray, while the outgoing ray is called reflected ray, and the line at right angle to the mirror surface at the point of incidence is called a normal. The mirror in this case is a plane mirror. It means that it is a flat mirror, raher than a curved mirror.
Law of reflection:
There are two laws of reflection. They apply to all types of mirrors.
1- The angle of incidence is equal to the angle of reflection.
i (Angle of incidence)= r (Angle of reflection)
2- The incident ray, the reflected ray and the normal all lie in the same plane.
Image through a plane mirror is a result of reflection of light.
Use of mirror (Periscope)
In a plane mirror the image is always the same size as the object.
Examples of plane mirrors include household ‘dressing’ mirrors, dental mirrors for examining teeth, security mirrors for checking under vehicles and periscope.
Periscope:
A periscope uses reflection to allow you to see above your normal line of vision – or even round corners.