Electromagnetic radiation (EMR) - Term Paper Example

Tuesday, June 2, Radiation Introduction Electromagnetic radiation otherwise abbreviated as EMR refers to forms ofenergy which are produced by oscillating magnetic and electric disturbances or by movement of electrically charged particles travelling through matter or a vacuum (Nikita , Kevin and Mateo). Mostly, Electromagnetic Radiation is in the forms of waves. These waves include: Radio Waves, Microwaves, Infrared, X- rays and Gamma-rays (Mattson). The magnetic and electric fields resulting in the electromagnetic waves interact by coming together at right angles to each other and these combined waves move perpendicular to both electric and magnetic oscillating fields and as a result, the disturbance is caused (Nikita , Kevin and Mateo). The resulting electron radiation is released in bundles of light energy which travel at a speed of 299 792 458 m / s, equivalent to the speed of light, as quantized harmonic waves. This electromagnetic waves are grouped according to their wavelength and the this results in the electromagnetic spectrum. The resultant magnetic and electric waves move perpendicularly to each other having certain characteristics which are Amplitude, frequency and wavelength. Features of Electromagnetic Radiation Wavelength The movement of the electromagnetic waves is in form of patterns. The distance that exists between two peaks is the wavelength of the wave. The wavelength of a waveform is measured in meters. This is illustrated in the figure below. Frequency Frequency can be defined as the number of oscillations of the wave per unit time. The frequency of waves is not constant, it varies and the variation greatly depends on the type and nature of the electromagnetic radiation. The frequency of a wave is measured in Hertz. The wave can have high frequency or low frequency as indicated in the diagram below. The frequency is related to the wavelength by the dispersion relation is given by: Where  the wavelength and c is the propagation speed Amplitude Amplitude refers to the characteristic height of the wave. Amplitude is a measure of the intensity of the wave and is measured in meters. The amplitude of an electromagnetic radiation is given by Where  Refers to the electrical amplitude,  is the wavelength and c is the propagation speed. Characteristics of electromagnetic Radiation Interference This is the process in which two waves superposes to form one resultant wave. For interference to occur, the source of the waves must be coherent. If two electromagnetic waves having the same frequency get together i.e. they superpose, it results into a wave which has the resultant magnetic and electric field strength equal to the sum of fields of the two waves. When two strong waves moving that have their fields moving in one direction, i.e. same direction in time and space, the resulting waveform is twice that of each individual waveform (Encyclop?dia Britannica Online). This results in constructive interference. However, the superposition of a wave having an electric field in one direction in space and with another electromagnetic radiation wave which has the same frequency but with an electric field in the opposite direction in space and time results in cancellation and a result, there is no formation of a waveform (Encyclop?dia Britannica Online). This implies that the two waves are not in phase. The resultant effect is termed as destructive interference. In summary, superposition of waves results in destructive, constructive or partial interference considering the magnitude of the waves being superposed. If two monochromatic waves described by And Then The value is responsible for the interference process. If then the resultant interference is constructive If Then  If Then the interference is a destructive interference. Diffraction When electromagnetic waves come onto obstacles, they are diffracted. Diffraction is the process by which the waves bend around obstacles. This can be illustrated as in the diagram below. This process occurs inn electromagnetic radiation waves such as X – rays, gamma rays and sound waves. The diffraction of waves may result in interference. This is due to the fact when waves superimpose, the result is either reinforcement of each other or cancellation of each other. The unobstructed point which is on the wave front results in secondary waves. Electromagnetic Radiation Types There are various types of electromagnetic radiation types. This are: Radio Waves, Microwaves, Infrared, X- rays and Gamma-rays (Mattson). The figure schematic diagram below shows the electromagnetic spectrum. Visible light This is a type of an electromagnetic radiation which can be viewed by the human eye. This are perceived as colors ranging from the longer wavelengths, red which has a wavelength approximately equals to 700 nanometers, to the shorter wavelengths – violet which has a wavelength of approximately 700 nanometers. Radio Waves These are electromagnetic radiation waves with the longest wavelength in the electromagnetic spectrum. Micro waves Micro waves refs to a band of waves found in the higher frequency region of the electromagnetic spectrum. These waves have a longer wavelength than visible light. These waves easily penetrate through dust, cloud, rain and smoke. These are used in Global Positioning Receivers and most communications satellites to send signals. Infrared These are electromagnetic radiation with a frequency ranging from 2,500 nanometers to 16,000 nanometers. This type of electromagnetic radiation has a corresponding frequency of ranging 1.9 *1013 Hertz to 1.2 * 1014 Hertz. Ultraviolet This type of waves have shorter wavelength than the visible light. This wave is divided into three regions basing on the amount of energy each possesses. These are near ultraviolet, extreme ultraviolet and far ultraviolet. Works Cited Encyclop?dia Britannica Online. Electromagnetic Radiation. 2013. 13 March 2013 . Mattson, Barbara. Electromagnetic Spectrum. 03 February 2010. 13 March 2013 . Nikita , Patel, Vo Kevin and Hernandez Mateo. Electromagnetic Radiation. 12 May 2010. 13 March 2013 . Read More