PowerPoint Presentation(A partial fulfillment in Physics)

Presented By:

Mary Joice AvinanteOrlane Marybhell Dimaunahan

Klarabelle VillafrancaNikko SamonteJonas Villaveza

IV-1

BaStateU\ ARASOFNasugbu Batangas

A.Y.2011-2012

Light

Waves

What is Light?This question has been a puzzle for centuries.

People once thought light was something that traveled from a person’s eyes to an object and then back again. If anything blocked the rays from the eyes, the object could not be seen. Since the 1600’s, scientists have made many discoveries about light.

Light -An electromagnetic wave, a form of energy

that can travel freely across space. - an electromagnetic radiation in the

wavelength range extending from about 0.4 micro to about 0.7 micro or perhaps more properly, the visual response to electromagnetic radiation in this range.-a transverse wave, meaning that the vibrations are perpendicular to the motion and speed of the wave.

Different Theories About LightCorpuscular theory -light consist of tiny particles that travel

in straight lines through space. Sir Isaac Newton called these particles corpuscles.

Wave theory -Christian Huygens asserts that light is a form of wave motion sent out by luminous bodies.

Electromagnetic theory-James Clark Maxwell explains that light is the result of the oscillations of the electrically charged particles of the atom.

Quantum theory-Max Planck advanced the idea that light is an energy called photons or quanta which are transmitted in small bundles or quantities from luminous bodies and which, upon entering the eyes, make us able to see.

Characterization of lightPolarized light- a form of light that

vibrates in one plane only.

Coherent light-is a form of light, the constituent wave trains of which are emitted by single source and move in unison. This form of light comes from laser.

Interference- phenomenon of light or any other

types of waves in which two or more waves can combine to yield a resultant wave whose amplitude or intensity maybe greater or less than the component wave.

Constructive Interference-the two crest add together to give a

larger crest. It gives a brighter light than either wave would have separately.

Destructive Interference-the trough reduces the height of the

crest, leaving the spot dim or even dark.

Types of Interference

Sources of LightNatural sources of lightSun

Stars

Artificial Sources of LightElectric light bulbs

Neon Signs

Candle

Fluorescent tubes

Different LawsLaw of Reflection

-when light strikes an object, it may be reflected, absorbed or refracted depending upon the nature of the surface of the material.

Law of Refraction-when a light ray passes obliquely from

one medium to a more dense optical medium, it is bent toward the normal.

How is light wave transmitted?Transparent body

-one which transmits light readilyTranslucent body

-one which transmits some light, but much of the light scattered or diffused.

Opaque body-one which does not allow or transmit

light at all.

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