Physics Project Mtb

7/30/2019 Physics Project Mtb

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COLLEGE, BALEWADI,

PUNEPHYSICS PROJECTON :-ELECTROMAGNETIC

WAVESMADE BY :-MRIT UNJA GUPTA


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INTRODUCTIONElectromagnetic radiation(EM radiation orEMR) is a form of energy emitted and absorbedby charged particles which exhibits wave-like behavior as it travels through space. EMR hasboth electric and magnetic field components, which stand in a fixed ratio of intensity to eachother, and which oscillate in phase perpendicular to each other and perpendicular to thedirection of energy and wave propagation. In a vacuum, electromagnetic radiation propagatesat a characteristic speed, the speed of light.EMR carries energysometimes called radiant energythrough space continuously awayfrom the source. EMR also carries both momentum and angular momentum. These propertiesmay all be imparted to matter with which it interacts. EMR is produced from other types ofenergy when created, and it is converted to other types of energy when it is destroyed.The photon is the quantum of the electromagnetic interaction, and is the basic "unit" orconstituent of all forms of EMR.

EMR is classified according to the frequency of its wave. The electromagnetic spectrum, inorder of increasing frequency and decreasing wavelength, consists of radiowaves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gammarays. The eyes of various organisms sense a somewhat variable but relatively small range offrequencies of EMR called the visible spectrum or light.


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MAXWELLS EQUATIONS FOR

EM FIELDS FAR FROM

SOURCESJames Clerk

Maxwell firstformally

postulated electromagnetic
http://en.wikipedia.org/wiki/James_Clerk_Maxwellhttp://en.wikipedia.org/wiki/James_Clerk_Maxwellhttp://en.wikipedia.org/wiki/James_Clerk_Maxwellhttp://en.wikipedia.org/wiki/James_Clerk_Maxwellhttp://en.wikipedia.org/wiki/James_Clerk_Maxwell


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PROPERTIES OF EMRThe physics ofelectromagnetic radiationis electrodynamics.Electromagnetism is the physicalphenomenon associatedwith the theory ofelectrodynamics. Electric

and magnetic fields obeythe propertiesof superposition. Thus, a

field due to any particularparticle or time-varyingelectric or magnetic field


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DUAL NATURE OF EMREM radiation exhibits both wave

properties and particle properties at the

same time (see wave-particle duality).Both wave and particle characteristicshave been confirmed in a largenumber of experiments. Wavecharacteristics are more apparent

when EM radiation is measured over


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WAVE MODEL Electromagnetic radiation is a transverse wave, meaning that the oscillations of the waves areperpendicular to the direction of energy transfer and travel. The electric and magnetic parts of the fieldstand in a fixed ratio of strengths in order to satisfy the two Maxwell equations that specify how one isproduced from the other. These E and B fields are also in phase, with both reaching maxima and minima atthe same points in space.An important aspect of the nature of light is frequency. The frequency of a wave is its rate of oscillationand is measured in hertz, the SI unit of frequency, where one hertz is equal to one oscillation per second.

Light usually has a spectrum of frequencies that sum to form the resultant wave. Different frequenciesundergo different angles of refraction.A wave consists of successive troughs and crests, and the distance between two adjacent crests or troughs iscalled the wavelength. Waves of the electromagnetic spectrum vary in size, from very long radio waves thesize of buildings to very short gamma rays smaller than atom nuclei. Frequency is inversely proportionalto wavelength, according to the equation:-where vis the speed of the wave (cin a vacuum, or less in other media), fis the frequency and is thewavelength. As waves cross boundaries between different media, their speeds change but their frequenciesremain constant.Interference is the superposition of two or more waves resulting in a new wave pattern. If the fields havecomponents in the same direction, they constructively interfere, while opposite directions cause destructiveinterference. An example of interference caused by EMR is electromagnetic interference (EMI) or as it ismore commonly known as, radio-frequency interference (RFI).The energy in electromagnetic waves is sometimes called radiant energy.


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PARTICLE MODEL AND

QUANTUM THEORYAn anomaly arose in the late 19th centuryinvolving a contradiction between the wave theory oflight on the one hand, and on the other, observers'

actual measurements of the electromagnetic spectrumthat was being emitted by thermal radiators knownas black bodies. Physicists struggled with this

problem, which later became known as the ultraviolet

catastrophe, unsuccessfully for many years. In1900, Max Planck developed a new theory of black-body radiation that explained the observed spectrum.Planck's theory was based on the idea that blackbodies emit light (and other electromagnetic


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SPEED OF PROPAGATIONAny electric charge thataccelerates, or any changing

magnetic field, produceselectromagnetic radiation.

Electromagnetic information aboutthe charge travels at the speed oflight. When any wire (or other

conducting ob ect such as


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ELECTROMAGNETIC

SPECTRUMIn general, EMradiation (thedesignation'radiation'

excludes staticelectric and

magnetic


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RADIO AND MICROWAVE

HEATING AND CURRENTSWhen EM radiation interactswith matter, its behaviorchanges qualitatively as its

frequency changes. At radioand microwave frequencies,EMR interacts with matterlargely as a bulk collection ofcharges which are spread outover large numbers of affectedatoms. In electrical conductors,such induced bulk movementof charges (electric currents)results in absorption of the


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REVERSIBLE AND IRREVEVRSIBLE

MOLECULAR CHANGES BY VISIBLE

LIGHTAs frequency increases

into the visible range,photons of EMR have enoughenergy to change the bondstructure of some individualmolecules. It is not a

O G O


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PROPAGATION AND

ABSORPTION IN EARTHS

SURFACEMostelectromagnetic waves of

higherfrequencythan visibl


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ELECTROMAGNETIC

RADIATIONS AS A FORM OF

HEATThe basic structure of matter involves chargedparticles bound together in many different ways.When electromagnetic radiation is incident on

matter, it causes the charged particles to oscillate andgain energy. The ultimate fate of this energy dependson the situation. It could be immediately re-radiatedand appear as scattered, reflected, or transmitted

radiation. It may also get dissipated into othermicroscopic motions within the matter, coming

to thermal equilibrium and manifesting itselfas thermal energy in the material.Infrared radiation in the spectral distribution of


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CONCLUSIONIN THIS PROJECT, WE SAW THATELECTROMAGNETIC WAVES PLAY A VERYLARGE PART IN OUR TECHNOLOGY, EVERYDAY

LIFE AND ALSO IN THIS NATURE. DIFFERENTUSES AND THEORIES RELATED TOELECTROMAGNETIC WAVES WERE ALSOSTUDIED.


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BIBLIOGRAPHYWWW.GOOGLE.COMWWW.WIKIPEDIA.COMPHYSIC, STANDARD XIITH, MSBSHSE

PHYSICS, XIITH, NCERT

CONCEPTS OF PHYSICS, H.C. VERMAFUNDAMENTALS OF PHYSICS, RESNICK &HALLIDAY, JEARL WALKER
http://www.google.com/http://www.wikipedia.com/http://www.wikipedia.com/http://www.google.com/


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