SCIENCE PROJECT

Made by :- AbhiroopVIII-B

LIGHT

Important Point of light

• 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.

Convex lens

Concave lens

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

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.

Law of reflection

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)].

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 

Diffuse reflection

Regular Reflection

Reflection from a smooth surface like that of a mirror is called regular reflection or specular.

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

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.

CARE OF EYES

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.

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.

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