3. •
•
•
•
•
•
Light along straight line.
Any smooth surface which reflect a light is called
mirror .
An image which can be obtained on screen is called
Real Image.
An image which can’t be obtained on screen is called
Virtual image.
An image formed by an convex mirrors is erect ,
virtual & smaller in size than the object.
An image formed by concave lens is erect , virtual &
smaller in size than the object.
4.
5.
6. Types Of Rays
There are two types of rays:1)-Incident Rays:-the light rays , which strikes any surface ,is called
Incident Rays.
2)-the rays that comes back from the surface after reflection is known as
Reflected Ray
7. Law of reflection
The laws of reflection are as follows:
1)-The incident ray, the reflected ray and the normal to the reflection
surface at the point of the incidence lie in the same plane.
2)-The angle which the incident ray makes with the normal is equal to the
angle which the reflected ray makes to the same normal.
3)-The reflected ray and the incident ray are on the opposite sides of the
normal.
8. Angle Of Reflection
a)-The line (marked as N) is known as normal to the reflected surface at that
point.
b)-The angle between the normal & incident ray is called angle of incidence
[angle ( i)].
c)-The angle between the normal & reflected ray is known as angle of reflection
[angle (r)].
9. Diffuse reflection
Diffuse reflection is the reflection of light from a surface
such that an incident ray is reflected at many angles rather
than at just one angle as in the case of specular reflection.
An illuminated ideal diffuse reflecting surface will have
equal luminance from all directions in
the hemisphere surrounding the surface
11. A kaleidoscope is a cylinder
with mirrors containing loose, colored
objects such as beads or pebbles and
bits of glass. As the viewer looks into
one end, light entering the other
creates a colorful pattern, due to
the reflection off of the mirrors
12. Human Eye
The human eye is an organ which reacts to light for several purposes. As a conscious
sense organ, the mammalian eye allows vision. Rod and cone cells in the retina allow
conscious light perception and vision including color differentiation and the
perception of depth. The human eye can distinguish about 10 million colors.
a)-The transparent front part of eye is called CORENA .
b)-Behind the cornea, we find dark muscular structure called IRIS .
c)-In the iris , there is a small opening called the PUPIL.
d)-We are able to see with the help of RETINA.
13. CARE OF EYES
We should take care of our eyes. We should not…:a)
Look at the sun or powerful light directly.
b)
Never rub your eyes, with dirty hands.
c)
Always read at normal distance for vision.
d)
Don’t see T.V or computer for long time.
14. Louis Braille
Louis Braille (4 January 1809 – 6 January 1852) was
the inventor of Braille, a system of reading and
writing used by people who are blinder visually
impaired.