Module 13 Physics X Light-1.ppt, Starting

start studying from this ppt for more such ppts just comment below..

2. Light
THIS UNIT CONTAINS -
1.Properties of
light
2.Reflection
3.Refraction

3. WHAT IS LIGHT?
Light is a form of energy
which enables us to see
or helps in vision.

4. Properties of Light
Light travels in straightlines:
Laser

5. Light travels VERY FAST –around
300,000 kilometres per second.
At this speed it can
go around the world 8
times in one second.

6. Light travels much fasterthan sound. For example:
1)Thunder and lightning
start at the same time,
but we will see the
lightning first.
2) When a starting pistol
is fired we see the
smoke first and then
hear the bang.

7. We see things because they
reflectlight into our eyes:
Homework

8. Shadows
Shadows are places where light is “blocked”:
Rays of light

9. Properties of Light summary
1)Light travels in straight lines
2)Light travels much faster than sound
3)We see things because they reflect light
into our eyes
4)Shadows are formed when light is blocked
by an object

10. Reflection
Reflection from a mirror:
Incident ray
Normal
Reflected ray
Angle of
incidence
Angle of
reflection
Mirror

11. DEFINITION
•It is the phenomenon in which a ray
of light after falling on a smooth and
polished surface returns back into
the same medium.

12. The Law of Reflection
1.Angle of incidence = Angle of reflection
In other words, light gets reflected from a surface at
the same angle it hits it.
The
same !!!

13. 2.Incident ray,reflected ray & normal at
the point of incident lie on the same
plane
Incident
ray
Reflect
ed ray
normal

14. Regular and Diffuse Reflection
Smooth, shiny surfaces
have a clearreflection:
Rough, dull surfaces have
a diffuse reflection.
Diffuse reflectionis when
light is scattered in
different directions

15. HOME ASSIGNMENT
•Read chapter from NCERT (Pg. no. 161 and
162)