Light is a form of energy which . Light is needed to see thing saround Us.
Light can be detected with our eyes
Light enables us to see objects from which it comes or from which it is reflected.
The objects which has their own light/which can emit light are called luminious objects
Example- Sun,Electric bulb,Tube Light,Glowing candle etc.
The objects which dont have their own light but only reflects or scatter the light falling upon them are called nun-luminous objects.
Table,Bench, flower Etc.
Can you answer ?
Is moon aluminious object or num luminious objects
Remember
Light isa form of energy . which causes the senstion of sight.
Light travels in straight line
Nature Of lIght .
Is light shows dual nature ?
- There are two theories About the Nature of light.
- 1. Wave theory of Light
- 2. Particle Theory of Light
- Wave Theory Of Light –
- According to this theory light consists of electronic waves.
- Light Does not require any medium (Solid,Liquid,Gas ) for their propagation.
- The Speed of light is 3*10^8 m/s.
- The phenomena of Diffraction ,Interferance , polarazaion can be explained with wave theory of light
2. Particle theory of light
- Light is composed of particles which travels i straight line at very high speed.
- The elementary particles which defines light is called photon.
- The phenomena of reflection refraction casting of shadows can be explained with particle theory of light
Depending on situation light can show both particle and wave theory of light
Light Exhibits the propoties of both wave theory as well as particle. So modern theory of light called quantum theory of light.
Reflection of light
when light falls on the surface of the object ,some ofit is sent back.
The process of sending back the light rays which fall on the surface of an object is caled refclectoon
In the Figure The Light Falling on the mirror is called Incident ray
The Light coming away from the mirror is the reflected ray
The objects having polished ,shinning surface reflect more light than objects having unpolished ,dull surface
Silver metal is one of the best reflectr of light
ordinary miror is made by depositing a small layer of thin luminium coating.
silver can also be used for making mirror. but as it is costly hence aluminiumis used for coarting
Reflection of light from plane surface :Plane Mirror
The point on which light falls is called point of incidence
The normal is a line at right angle to the mirror surface at the point of incidence
The angle of incidence is the angle made by the incident ray with the normal at the point of incidence
The angle of reflection is the angle made by the reflected ray with the normal at the point of incidence.
