19-10-2012, 12:32 PM
ELECTROMAGNETIC WAVE
ELECTROMAGNETIC WAVE.docx (Size: 98.28 KB / Downloads: 72)
INTRODUCTION
When we tune on our radio, watch tv, send a text message, or pop popcorn in a microwave oven, weare using electromagnetic wave. we depend on this energy every hour of every day. Without it, the world we know could not exist.
if it is so see how to creating an electromagnetic wave.
According to putter, et al( 2009), The electric energy of the moving electrons produces the energy of the electric field, which produces the energy of the magnetic field, which produces the energy of the magnet. The energy of the electric and magnetic fields is in the form of an electromagnetic wave. This electromagnetic wave travels at the speed of light.
Pradeep, et al (2001), viewed that similar kind of EM wave introduction. Electromagnetic wave is an energy wave produced from an electrical discharge. Electromagnetic waves have rise and fall cycles. The number of rise and fall cycles per second is its frequency. We can’t see or feel them, but they are around us.
PROPERTICE OF EM WAVE
The source that produce them and methods of their detection are different, but they have the following common properties :
From the view of Anil kumar, et al (2003) , Electromagnetic radiation is characterized by a broad range of wavelengths and frequencies, each associated with a specific intensity (or amplitude) and quantity of energy.
According to putter, et al( 2009),Electromagnetic waves in general, is that no medium is required for the wave to travel through. Other waves, such as sound waves, can not travel through a vacuum. An electromagnetic wave is perfectly happy to do that. An electromagnetic wave, although it carries no mass, does carry energy. It also has momentum, and can exert pressure (known as radiation pressure). The reason tails of comets point away from the Sun is the radiation pressure exerted on the tail by the light (and other forms of radiation) from the Sun.
How each property varies along the spectrum?
Microwave
• Frequency between 300MHz to 300GHz.
• Wavelength from 1m to 1mm
• Used in microwave appliances , radar , spectroscope , navigation , radio astronomy
• Named micro because of they are shorter than most waves used in broadcasting .
Xrays
• Frequency from 30petahertz to 30exhertz.
• Wavelength from 100ev to 100kev
• Funfact : in some languages X radion is called Rantgen radiation , after this discover
• Xrays are used to image bones in medicine
• X rays do not pass through lead
Radio
• Frequency 300GHz to 3KHz
• Wavelength of 1mm to 100km
• Transmitter music and shows radio receiver
• Astronomers used radio waves from celestial bodies to learn about them . cosmic background radiation in the form of radio waves .
Infrared
• Frequency of 1 to 40THz
• Wavelength of 750nm to 1mm
• Used night vision , thermal analysis , reading CD ROMs
• Thermal radiation is in the infrared spectrum
Conclusion
An electromagnetic wave is any disturbance in the electric and magnetic fields that propagates All electromagnetic waves propagate at the speed of light in a vacuum. Electromagnetic waves can have any wavelength or frequency. There are types of electromagnetic are many Electromagnetic spectrum used to extend the frequency of very low frequencies to frequencies the highest possible. These include the waves of life, such as, radar, cooking, etc.