An overview of the characteristics of electro magnetic radiation

electromagnetic radiation pdf

Electrodynamics is the physics of electromagnetic radiation, and electromagnetism is the physical phenomenon associated with the theory of electrodynamics. When these waves pass through matter, they slow down slightly, according to their wavelength.

All types of electromagnetic waves travel at the speed of light in vacuum.

Properties of electromagnetic waves wikipedia

Neither of these behaviours are responsible for EM radiation. The lower part of this range may also be called microwaves or terahertz waves. Constructive interference occurs when two or more waves are in phase and and their displacements add to produce a higher amplitude. The opposite effect occurs when an electromagnetic wave hits matter. Overview of Electromagnetic Waves by Ron Kurtus revised 15 February Electromagnetic waves consist of oscillating electrical and magnetic fields, acting perpendicular to each other. They are the deep red rays you get from a heat lamp. Electromagnetic waves can show interference superimposition of two waves over each other. Wavelengths are also related to temperature. As the temperature increases, the wavelength of maximum emission decreases. Visible radiation light Main article: Visible spectrum Above infrared in frequency comes visible light. Further, as they are vector fields, all magnetic and electric field vectors add together according to vector addition. What is the frequency of a wave with a wavelength of cm? They are used for irradiation of foods and seeds for sterilization, and in medicine they are occasionally used in radiation cancer therapy. Both processes for producing electric and magnetic EMR fields have a different dependence on distance than do near-field dipole electric and magnetic fields.

Electromagnetic theory Electricity and magnetism were once thought to be separate forces. Ionizing radiation holds a great amount of energy to remove electrons and cause the matter to become ionized.

An overview of the characteristics of electro magnetic radiation

Electromagnetic waves are formed when an electric field shown in red arrows couples with a magnetic field shown in blue arrows. What are the characteristics of electromagnetic waves? An Overview of the Properties of Electromagnetic Waves Oscillating electric and magnetic fields form electromagnetic waves. Sources of short wavelengths By smashing high-energy electrons into other particles, such as atoms in a metal, X-rays are created. Currents directly produce a magnetic field, but it is of a magnetic dipole type that dies out with distance from the current. The higher energy shortest wavelength ranges of UV called "vacuum UV" are absorbed by nitrogen and, at longer wavelengths, by simple diatomic oxygen in the air. Typically, lower-energy radiation, such as radio waves, is expressed as frequency; microwaves, infrared, visible and UV light are usually expressed as wavelength; and higher-energy radiation, such as X-rays and gamma rays, is expressed in terms of energy per photon. Electromagnetic waves can be polarized , reflected, refracted, diffracted or interfere with each other. X-rays X-rays are roughly classified into two types: soft X-rays and hard X-rays. When electrons move back and forth or oscillate, their electric and magnetic fields change together, forming an electromagnetic wave. Physical processes that are relevant for this range are similar to those for visible light. Electromagnetic radiation can exert pressure known as the radiation pressure. The ratio of the refractive indices of the media determines the degree of refraction, and is summarized by Snell's law. Infrared Infrared is in the range of the EM spectrum between microwaves and visible light.

In reception of radio waves, the oscillating electric and magnetic fields of a radio wave couple to the electrons in an antenna, pushing them back and forth, creating oscillating currents which are applied to a radio receiver.

Radio waves are also used for navigation in systems like Global Positioning System GPS and navigational beaconsand locating distant objects in radiolocation and radar.

electromagnetic radiation in chemistry

This distance is given in meters m or fractions thereof. Magnetic poles come in pairs that attract and repel each other, much as electric charges do.

electromagnetic spectrum diagram

Sunburnfor example, is caused by the disruptive effects of middle range UV radiation on skin cellswhich is the main cause of skin cancer.

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Overview of Electromagnetic Waves by Ron Kurtus