The medium
in which light travels faster is known as rare medium.
The medium
in which light travels slower is known as denser medium.
Air is rare than water.
Water is rare than glass.
The light ray that strikes a surface is called incident ray.
The light ray
that bends in the second medium is called refracted ray.
An imaginary perpendicular line which is drawn at the point of
incidence of light ray is called Normal.
When light goes from air to glass it bends towards the normal at the interface
is called angle of incident.
When light leaves the glass it bends away
from the normal is called angle of refraction.
The angle of refraction is smaller than the angle of
incidence.
When light travels from a rarer to denser medium it bends
towards the normal.
When light
travels from denser medium to rarer medium it bends away
from the normal.
The angle the ray then makes with the normal inside the glass is called the critical
angle.
When the
incident ray falls normally to the surface of glass slab, then
there is no bending of ray of light and it goes straight.
Speed of light in air is 3×108 m/s.
Speed of light in glass is 2×108m/s.
Refractive index of water is 1.33.
Refractive
index of glass is 1.5.
Refractive index ofair is 1.0003.
Highest refractive index of diamond is 2.42.
Periscope is a long tube at the two ends of which are adjusted to
two totally reflecting prisms.
In the periscope the ray of light
from an object are totally reflected through an angle 900by
eachprism.
In the year 1665, Newton discovered by his
experiments with glass prisms that white light (sun light)
consists of a mixture of seven colors.
The phenomenon of splitting up of white light into its component
colors is called dispersion of light.
Rainbow is the example of dispersion of whit light. The rainbow upper
color isred and lower color is violet.
Seven colors are Red, Orange, Yellow, Green, Blue, Indigo, and
Violet. Or VIBGYOR. For Remembering this colors…(YOUR
BIG)…..(YOVR BIG)
Red, Green, and Blue are called primary
color of light.
The colors produce by mixing any two primary colors are called secondary
colors.
a)Red + Green = Yellow
b)Red + Blue =Magenta
c)Green + Blue = Cyan (peacock blue)
d)Red + Blue + Green= White
e)Yellow + Blue = White
f)Red + Peacock blue= White
g)Green + Magenta= White
When light
enters from one medium into another, its bends slightly from its original path.
This bending is called………………..
a) Reflection
b) Refraction
c) Dispersion
d) Total internal reflection
When light enters from air into glass it bends reflection…………………... a) Towards normal b) Away from normal c) Does not change the path d) all the light is reflected
After rain, when sunlight falls on tiny rain drops suspended in the air, rainbow is produced due to……… a) Reflection of light b) Refraction of light c) Dispersion of light d) Diffraction of light
After rain, when sunlight falls on tiny rain drops suspended in the air, rainbow is produced due to……… a) Reflection of light b) Refraction of light c) Dispersion of light d) Diffraction of light
