Refraction

Define refraction of light:
when light passes from one transparent medium to another, it changes speed and direction . this bending of light is called refraction

Effects of refraction:

1. whenever we open our eyes we observe the refraction of light . the lens in our eye refracts light to form image on the retina of our eye

2. refraction causes the formation of the rainbow.

3. Refraction takes place in lenses in spectacles , telescopes , magnifying glasses

Refraction in different mediums:

When light passes from air to water or glass , it bends towards the normal . the angle of incidence is greater than the angle of refraction..

When light passes from water or glass to the air it bends away from the normal . the angle of refraction is greater than the angle of incidence

Incident Ray:

The ray of light that falls on the surface of the other medium.

Refracted Ray:

The ray of light that changes its direction in the other medium.

Angle of Incidence:

The angle between the normal and the refracted ray . it is denoted by ' i '

Angle of Refraction:

The angle between the normal and the refracted ray . it is denoted by ' r '

Law of Refraction:

There are two laws of refraction.

1. The incident ray the refracted ray and the normal at the point of incidence all lie in the same plane.

2. For two particular mediums the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant