Causes of Reflection

• When a ray of light is reflected from a smooth surface, the angle of incidence is equal to the angle of reflection (i = r).

• The incident ray, the reflected ray and the normal all lie in the same plane.

Phenomenon of refraction

Diagram of refraction

Meaning of refraction

•   refraction of light is the change in direction or bending of the light as it enters from one medium to another.
•  It is caused by the change in the velocity in which the velocity of light is lower is an optically denser medium.
• Refraction is  described by snell’s law ,which states that when a ray of light travels from vacuum (or air) at an angle of incidence ,I and refracted into a medium at an angle of refraction ,r.
•  n= sin i / sin r

Application of convex mirror

qRear-view Mirror

•Convex mirror are used as rear-view mirror in motor vehicles to give drivers a wide-angle view of the vehicles behind them.

qWide-angle view Mirror

•  Concave mirror are hung from the corners of supermarket ceilings to provide a wider field of vision of the activities taking place in the shopping areas.

qSafety mirrors

•Convex mirrors are also mounted at sharp corners of roads so that drivers are able to see oncoming cars on their blind slide.

Applications of concave mirror

     Reflector

Concave parabolic mirror are used as reflectors in torch light and car headlight. 
Magnifying Mirror

Concave mirror in dentist’s mirror magnifies the image so that the dentist can get a closer look at the teeth.

Make-up Mirror 
For this purpose ,a wide-aperture concave mirror with a large radius of curvature is used.

Application1-reflection

One application is in the construction of telescopes, microscopes, CD-ROM drives, and other devices that use optical devices. The reflection of light, through lenses or against mirrors, is highly important. Symmetry is also used in graphic design, engineering, and architecture, to create stable and/or visibly pleasing buildings, signs, graphics, logos, etc.

Convex mirror

Differences between concave mirror and convex mirror

•Rays parallel to the principal axis converge to a point, called the real focal point, on the principal axis.

•PF = Focal length ,f

           = Distance between the real    focal point and the pole of  the mirror

        Example :f=+20cm

Concave mirror

 

Specular reflection

Diagram of reflection

Laws of reflection

• When a ray of light is reflected from a smooth surface, the angle of incidence is equal to the angle of reflection.

• The incident ray, the reflected ray, and the normal all lie in the same plane.