physics

Electromagnetic Waves : 

Electromagnetic Waves PHYSICS PROJECT ABHINAV GUPTA

ACKNOWLEDGEMENT : 

ACKNOWLEDGEMENT I wish to express our deep sense of gratitude to those whose encouragement and cooperation has been a source of inspiration . It’s an honour to thank our principal , Ms. Archana Nigam , Delhi Public School, Kalyanpur , Kanpur for providing me the opportunity to make this project and learn through it. We would like to thank MR.VIJAY SRIVASATAVA for providing us the right direction and for his cooperation and help in successful completion of our project. I are indebted to both of them for their help. ABHINAV GUPTA XII

About Electromagnetic Waves: 

About Electromagnetic Waves When you listen to the radio, watch TV, or cook dinner in a microwave oven, you are using electromagnetic waves. Radio waves, television waves, and microwaves are all types of electromagnetic waves. They differ from each other in wavelength. Wavelength is the distance between one wave crest to the next.

Properties of Electromagnetic Waves: 

Properties of Electromagnetic Waves Electromagnetic Wave - A transverse wave consisting of oscillating electric and magnetic fields at right angles to each other. The spectrum includes more than visible light- not all light is visible to the human eye. Light is a wave and also a particle.

The Electromagnetic Spectrum: 

The Electromagnetic Spectrum Electromagnetic waves vary depending on frequency and wavelength

Properties of the Electromagnetic Spectrum: 

Properties of the Electromagnetic Spectrum Waves in the electromagnetic spectrum vary in size from very long radio waves the size of buildings, to very short gamma-rays smaller than the size of the nucleus of an atom. Did you know that electromagnetic waves can not only be described by their wavelength, but also by their energy and frequency? This means that it is correct to talk about the energy of an X-ray or the wavelength of a microwave or the frequency of a radio wave. The electromagnetic spectrum includes, from longest wavelength to shortest: radio waves, microwaves, infrared, optical, ultraviolet, X-rays, and gamma-rays.

Different types of waves : 

Different types of waves Gamma Rays - Shortest wavelength. Used in cancer treatment and food irradiation. X Rays - 6 th longest wavelength. Medical exam of teeth and bones. Ultraviolet Light - 5 th longest wavelength . Sterilization Visible Light - 4 th longest wavelength. Microscope, astronomy Infrared Waves - 3 rd longest wavelength. Infrared photography, night vision Microwaves - 2 nd longest wavelength. Radar, Microwaves Radio Waves - longest wavelength. AM/FM, TV

Gamma Rays: 

Gamma Rays Wavelenght range : 1 X 10 -14 to 1 X 10 -10 m Frequency range : 3 X 10 22 to 3 X 10 18 Hz Production : By transitions of nuclei and decay of certain elementary particles. Properties : Chemical reaction on photographic plates, fluorescence, ionisation, diffraction , highly-penetrating , chargeless. Uses : Provide information about structure of atomic nuclei .

X-Rays: 

X-Rays Wavelenght range : 1 X 10 -11 to 3 X 10 -8 m Frequency range : 3 X 10 22 to 3 X 10 18 Hz Production : By sudden deceleration of high-speed electrons at high-atomic number targets Properties : All properties of gamma rays but less penetrating Uses : For studying structures of inner atomic shells To cure untraceable skin diseases, like cancer

Ultraviolet Waves: 

Ultraviolet Waves Wavelenght range : 1 X 10 -8 to 4 X 10 -7 m Frequency range : 3 X 10 16 to 8 X 10 14 Hz Production : By sun, arc, vaccum spark Properties : All properties of gamma rays but less penetrating, produce photo- electric effect. Uses : In detection of invisible writing, forged documents, fingerprints and to preserve foodstuffs, for sterlizing the surgical instruments.

Visible Light Waves: 

Visible Light Waves Wavelenght range : 4 X 10 -7 to 8 X 10 -7 m Frequency range : 8 X 10 14 to 4 X 10 14 Hz Production : Radiated by excited atoms in gases and incandescent bodies. Properties : Reflection, refraction, interference, diffraction, polarisation, photoelectric effect, sensation of sight. Uses : Reveals the structure of molecules and arrangement of electrons in external shells of atoms.

Infrared Radiation: 

Infrared Radiation Wavelenght range : 1 X 10 -7 to 5 X 10 -3 m Frequency range : 4 X 10 14 to 6 X 10 10 Hz Production : From hot bodies, and by rotational and vibrational transitions in molecules. Properties : Heating effect on thermopile and bolometer, reflection , refraction, diffraction Uses : For providing electrical energy to satellites by means of solar cells, for treating muscular strain, for weather forcasting,in green houses to keep the plants warm.

Microwaves: 

Microwaves Wavelenght range : 1 X 10 -3 to 3 X 10 -1 m Frequency range : 3 X 10 11 to 1 X 10 9 Hz Production : By oscillating currents in special vaccum tubes, and by electromagnetic oscillators in electric circuits. Properties : Reflection , Polarisation. Uses : In radar for aircraft navigation , long- distance wireless communication via satellities and in microwave ovens.

Radio Waves: 

Radio Waves Wavelenght range : 1 X 10 -1 to 1 X 10 4 m Frequency range : 3 X 10 9 to 3 X 10 4 Hz Production : By oscillating electric circuits. Properties : Reflection , Diffraction. Uses : In Radio and T.V. communication systems.

Speed of Electromagnetic Waves: 

Speed of Electromagnetic Waves All electromagnetic waves move at the speed of light Remember… Speed= wavelength x frequency Only the wavelength and frequency change This change decides which type of electromagnetic wave it is (radio, gamma, etc.)

Speed of Light: 

Speed of Light The speed of light in a vacuum = 2.99792458 x 10 8 m/s The speed of light in air = 2.99709 x 10 8 m/s We use 3 x 10 8 m/s which equates to 300 million meters per second !

BIBLIOGRAPHY: 

BIBLIOGRAPHY PHYSICS NCERT – PART I PHYSICS NCERT – PART II NOOTAN CBSE XII NIRMAL PHYSCIS LAB MANUAL WEBSITES – www.icbse.com www.googleimages.com