0Light- It is a form of energy which produces the sensation of sight.
Properties of light
- It is an electromagnectic wave.
- Light travels along a straight path that is rectilinear propogation of light.
- Speed of light in vacuum is 3×108 m/s
| A Ray of light | Beam of light |
| A ray of light is apath followed by light energy in a transparent medium | A group of parallel rays of light emitted by the source of light. |
Three types of beam of light
REFLECTION OF LIGHT
The process of returning back or bouncing back the light to the same medium after striking a surface is called reflection of light.
laws of reflection
1. Incident angle (θi) is equal to the reflected angle (θr).
θi=θr
2. Incident ray, Reflected ray and normal to the reflecting surface at the point of incidence lie in the same plane.
- Reflection of silver is highest that is approximately 95%
- reflection of coal is approx. 4%
TYPES OF REFLECTION
| REGULAR REFLECTION | DIFFUESD REFLECTION |
| when a parallel beam of light falls on a smooth and highly polished surface. | when a parallel beam of light falls on a rough surface. |
| the reflected beam is parallel | the reflected light is not parallel |
| reflected light is directed in a fixed direction | reflected light spread over wide area |
| e.g. search lights , polished shoes ,automobile headlights etc. | e.g. light reflected by wooden table ,newspaper etc. |
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