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THIS IS A PPT BASED IN THE BASICS OF LIGHT,MIRRORS AND LENSES.
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LIGHT : MIRRORS AND LENSES
LIGHT•Always travels in a straight line. This is the rectilinear propagation of light •Speed = 300,000 m/s•Travels in the form of wavelength
HITTING ANY SURFACE
When light hits any surface it may
1. Bounce back
2. Absorb
3. Pass through
REFLECTIONWhen light hits any surface and bounces back ,it is called reflection . There may be two types of reflection :Diffuse reflection Clear reflection
DIFFUSE REFLECTION From a rough
surface The rays may go
in any direction Image generally
not formed The surface will
not act as a mirror
CLEAR REFLECTION From smooth
and shiny surface
An image is formed
The surface will act as a mirror
NATURES OF IMAGES
Real : An image which forms on a screen
Virtual : An image which is formed inside the mirror
Erect :straight
Inverted : an image which is not straight
Lateral inversion : when left side appears on right and right appears on left side
REFLECTION IN A PLANE MIRROR
•NATURE OF THE IMAGE : •Laterally inverted•Erect•Same size•Distance between object and the mirror is same as the distance between the image and the mirror•Virtual
surface normal
sameangleincident ray exit ray
reflected ray
LAWS OF REFLECTION
•Angle of incidence = Angle of reflection•Normal , incident ray and the reflected ray , they all lie on the same plane.
Parallel rays
Reflected rays
RealFocus
Focal length = +Forms real, inverted,Reduced or enlarged
Image. Also formsVirtual, erect,
Enlarged images.
NATURE OF THE IMAGEOBJECT
IMAGE NATURE
BETWEEN P AND F
BEHIND THE MIRROR
ERECT,VIRTUAL,ENLARGED
AT F NO IMAGE -
BETWEEN C AND F
BEYOND C INVERTED,REAL,LARGE
AT C AT C INVERTED,SAME SIZE ,REAL
BEYOND C BETWEEN C AND F
INVERTED, REAL,SMALL
Parallel rays
Reflected rays
Virtual focus
Focal length = -Forms only virtual,
erect, reduced images betweenthe virtual focus and the mirror.
NATURE OF THE IMAGEOBJECT IMAGE NATUREBETWEEN P AND F
BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL
AT F BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL
BETWEEN C AND F
BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL
AT C BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL
BEYOND C BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL
focus (f)focus (f) 2 f2 fx x x x
Parallel rayPasses thruThe focus
Focal ray
Refracts parallelTo principal axis
A ray thru theCenter of the
lenses
Remains unbent
NATURE OF THE IMAGEOBJECT
IMAGE NATURE
BETWEEN P AND F
BEHIND THE MIRROR
ERECT,VIRTUAL,ENLARGED
AT F NO IMAGE -
BETWEEN C AND F
BEYOND C INVERTED,REAL,LARGE
AT C AT C INVERTED,SAME SIZE ,REAL
BEYOND C BETWEEN C AND F
INVERTED, REAL,SMALL
f2 f f 2 fFocal ray
Parallel ray
Ray thru center
Image is:VirtualErectReducedAppears on sameSide as object
NATURE OF THE IMAGEOBJECT IMAGE NATUREBETWEEN P AND F
BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL
AT F BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL
BETWEEN C AND F
BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL
AT C BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL
BEYOND C BETWEEN P AND F(INSIDE THE MIRROR)
VIRTUAL,ERECT,SMALL