Reflection and refraction of light and their uses

 LIGHT

Light is a type of energy that sensitizes our eyes. Because of which we see things.

Property of light

1. The speed of light in vacuum is 3 X 108.
2. The wavelength of visible light ranges from 3900 A to 7800 A.
3. Light moves in a straight line in the form of electric waves.
4. We can see objects due to light

NOTE 

The objects which produce light are called luminous objects.
Ex. Sun, candle, bulb etc.
And the objects which do not produce light are called non-luminous.

 Types of light rays 

There are three types of rays of light –

1. Parallel ray  These rays are parallel at all points.
   
   
   
2. Convergent ray  These rays emerge from the source and meet at any one point.

   

   
   
3. diverging rays  These rays appear to be spreading from the source, these rays are just the opposite of convergent rays.

   

Optical mediums

The medium through which light passes is called optical medium. There are three types of optical medium –

 1 – Transparent medium:- The medium through which light passes easily is called a transparent medium. Like- vacuum, air, glass etc. 

2 – Translucent medium:- The medium through which some part of the light passes through is called a translucent medium. Like – water, curtain etc. 

3 – Opaque medium:- The medium through which light cannot pass through is called an opaque medium. Like – wood, soil etc.

IMAGE

The shape of the object formed in the mirror is called image. Reflection is of two types –

 1 Real image This can be achieved on screen. If the rays of light traveling from a point actually meet at some other point after being reflected from the mirror, then the image formed will be real.