Wave is defined as a vibration or noise that crept. Electromagnetic power is a symptom caused by mechanical motion of a magnet. Magnets are objects that can generate attractive force or repulsive force on other objects (which may also be a magnet).
Basically the magnet is that there are rocks in the area whose name Magnesia around the Balkans or Asia Minor. Supposedly the story stuck to the shepherds sticks.
In general, waves propagate require an intermediary, such as surface water, air, fluid, gas, ropes, threads, wires, strings, and others.
James C. Maxwell (1873) then presented the paper at the Royal Society of British institutions on the emergence of a wave that can propagate without the need deliverer.
Experimental discovery of Electromagnetic Waves
Electromagnetic radiation is a combination of electric and magnetic fields which oscillate and propagate through space and carrying energy from one place to another. Visible light is one form of electromagnetic radiation. Theoretical research on electromagnetic radiation called electro dinamic, sub-field of electromagnetism.
Basic theory of electromagnetic wave propagation was first described in 1873 by James Clerk Maxwell in his papers at the Royal Society about the dynamics of electromagnetic field theory (the English language: A dynamical theory of the electromagnetic field), based on the results of his research work between 1861 and 1865.
In 1878 David E. Hughes was the first to send and receive radio waves when he found that the induced balance disturbance caused to the phone makes. He demonstrated his discovery to the Royal Society in 1880 but only say it was just an induction.
Was Heinrich Rudolf Hertz who, between 1886 and 1888, was first proved Maxwell's theory through experiment, demonstrating that radio radiation had all the properties of wave (now called Hertzian waves), and found that the electromagnetic equations can be formulated into a partial differential equation called the wave equation.
Electromagnetic waves discovered by Heinrich Hertz.
Each has an acceleration of electric charge emits electromagnetic radiation. When the wire (or delivers like antennas) delivers alternating current, electromagnetic radiation propagation at the same frequency with an electric current. Depending on circumstances, such as electromagnetic waves can be either a wave or as particles. As a wave, characterized by the velocity (speed of light), wavelength, and frequency. When considered as particles, they are known as photons, and each has the energy associated with the wave frequency is shown by the Planck relation E = Hν, where E is the photon energy, h is Planck's constant - 6626 × 10 -34 J • s - and ν is the frequency of the waves.
Einstein then update formula becomes Ephoton = hν.
Electromagnetic Research
Maxwell Review
Around the 19th century, Maxwell's equations expressed its quite shocking the world of Physics. One of them states the existence of electromagnetic waves. However, when it can not be proved. For that, Heinrich Hertz tried to prove the existence of electromagnetic waves it.
In theory, Hertz realized that Maxwell's electromagnetic waves which are a combination of electric waves and magnetic waves are perpendicular to each other. So also with the direction of motion. Because these waves sac electric waves, the Hertz tried to prove the existence of electromagnetic waves through the existence of electrical waves radiated by the transmitter circuit.
Hertz tried to make a simple transmitter circuit with the aid of voltage transformers and capacitors to strengthen as the container cargo. Because there is a shift in the gap flow transmitter, there are expected to electromagnetic wave radiation to be emitted. Because in theory, from the sparks that arise will be generated electromagnetic wave. As a result, the receiver loop circuit which was just a circle-shaped wire without any given source voltage, electric spark had appeared on his gap. This proves there is electricity flowing through the radiation of a object. finally deliverer to loop. Because the feeling was not satisfied, Hertz tried to calculate the frequency of the loop.
It turns out the same frequency generated by frequency transmitter. This means that electricity derived from the transmitter on the loop itself. With this proved the existence of Maxwell's electromagnetic wave radiation. Hertz experiment was also triggered the discovery of wireless telegraph and radio by Marconi. This series is in the quartz glass to avoid UV rays.
The wave propagation of this phenomenal success evidenced by Heinrich Rudolf Hertz,
This electromagnetic wave created by the interaction of electric field (electric field) with the magnetic field (magnetic field) are perpendicular to each other (perpendicular) in the vine. Both these fields affect each other and cause each other repeatedly in circumstances.
This means that the electric field-magnetic-electric-magnetic field etc.
Hertz experiment result, we are familiar with the term wireless or shipping packages of energy in the electric field and magnetic field without using an intermediary or called as a point-to-pint electric jumpers. Which was then known as bluetooth
Electromagnetic Wave Spectrum
Electromagnetic waves which are formulated by Maxwell was stretched in a wide frequency range. As a wave phenomena, electromagnetic waves can be identified by frequency and wavelength. Light is electromagnetic waves as radio waves or X-rays. Each has a different use of the physics even though they describe a similar phenomenon, namely the wave phenomena, more specifically electromagnetic waves. They are distinguished by frequency and wavelength. The following figure shows the spectrum of electromagnetic waves.
electromagnetic wave spectrum
Radio waves
Of course you often watch TV, listen to the radio, or using mobile phones to communicate, right? Well, all electronic devices that use radio waves as the signal propagation.
Radio wave is a wave that has the smallest frequency or longest wavelength. Radio waves within a wide frequency range covering a few Hz to gigahertz (GHz or order of rank 9). These waves are generated by electronic devices in the form of an oscillator circuit (a combination of component variation and resistors (R), inductors (L) and capacitor (C)). Therefore, radio waves are widely used in telecommunication systems. Broadcast TV, radio and cellular telephone networks use radio waves in this wave range.
A telecommunications system that uses radio waves as a signal carrier information basically consists of a transmitter antenna and receiver antenna. Before propagation as radio waves, the signal information in various forms (the voice on the radio systems, voice and data in cellular systems, or sounds and images on the TV system) first modulated. Modulation here is simply stated as a merger between electric vibration information (eg voice on the radio system) with the radio frequency carrier wave. This merging produces a radio wave modulated. These waves propagation through space from transmitter to receiver.
Therefore, we know of the terms AM and FM. Amplitude modulation (AM) or amplitude modulation combines the power of vibration and the vibration amplitude changes bearer form. The frequency modulation (FM) or frequency modulation combines the power of vibration and vibration frequency of the carrier in the form of change.
Microwave
microwave ovens
Have you ever heard of an electronic device such as a microwave oven? Or, you may have used it for cooking? Microwave ovens use microwave properties (microwave) effects in the form of heat for cooking. In addition, microwaves are also used in radar and communications systems analysis of the structure of atoms and molecules.
Microwave frequency range extending from 3 GHz to 300 GHz. The frequency of this generated from oscillator circuits in electronic devices. Microwaves can be absorbed by an object and the heating effect on the object. A microwave-based heating systems can take advantage of this phenomenon is to cook it. Such systems are used in a microwave oven that can cook food in it evenly and in a short time (fast).
In a system of radar, microwaves emitted continuously in all directions by the transmitter. If any objects affected by this wave, the signal will be reflected by the object and received back by the recipient. This reflected signal will provide information that there was a near object to be displayed by the radar screen.
scanner
From time to transmitting signals received by the radar, the distance of the detected object can be known. Of course you can imagine a formula that can be used to calculate this distance, is not it? Yes, the distance is speed multiplied by time, and because the wave velocity is constant, then by knowing the time, distance can be calculated. Do not forget that the division by a factor of two is necessary because the signal distance commute. Please you write down the formula.
Radar systems used by aircraft and submarines. With the radar, aircraft and submarines capable of detecting the presence of other objects close to them. When bad weather where there are storms and weather disturbances that can interfere with vision, the presence of radar to help navigate the aircraft to determine their direction and position of the landing destination.
Infrared Rays
How the TV remote can be used to turn off or turn on the TV? Here the remote uses infrared light transmitter and receiver. Did you know that there are mobile phones equipped with infrared to transfer data from or to a mobile phone?
Infrared light (infrared / IR) included in the electromagnetic wave and in the frequency range 300 GHz to 40,000 GHz (10 ^ 13). Infrared rays generated by the process in the molecule and a hot body. It has long been known that a hot body due to activity (vibration) in which atomic and molecular considered to radiate heat wave in the form of infrared rays. Therefore, the infrared light is often called heat radiation.
Photo infrared radiant heat that works on the basis of an object can be used to make paintings of heat from an area or object. Hot paintings may depict the results of which area is hot and not. A painting of heat from one building can be used to determine which areas of the building that generate excessive heat that can be done the necessary repairs.
In the field of health, radiant heat in the form of infrared rays of the organs can be used as information on health conditions of these organs. This is very useful for physicians in the diagnosis and make decisions appropriate action patients. In addition, radiant heat in a certain intensity are believed to be used for the healing process of diseases such as smallpox, and gout.
results of an infrared photograph images of the human body for medical examination
In electronic technology, infrared rays have long been used as a medium of data transfer. Mobile phones and laptops equipped with infrared connectivity as one to connect or transfer data from one device to another device. Infrared function on cell phones and laptops run through IrDa technology (infra-red data acquitition).
Light or visible light
In the spectral range of electromagnetic waves, light or visible light occupies only a narrow band above the infrared light. Visible light frequency spectrum contains the frequency at which the human eye is sensitive to it. The frequency of visible light, extending between 40 000 and 80 000 GHz (10 ^ 13) or correspond with wavelengths between 380 and 780 nm (10 -9). Light that we feel everyday in this frequency range. Light is also produced through the process in the scale of atoms and molecules in the form of internal settings in the configuration of electrons.
A discussion of the light was so extensive and formed a separate disciplines of physics, namely optics.
Ultraviolet Rays
Frequency range of ultraviolet light (ultraviolet) stretches in the range 80 000 GHz to tens of millions GHz (10 ^ 17).
Ultraviolet rays or ultraviolet rays is also coming from solar ultraviolet radiation has an energy that is strong enough and able to ionize the atoms in the layer of the atmosphere. From the process of ionization of atoms is generated ions, which are electrically charged atoms. Layers consisting of these ions to form a special layer in the atmosphere called the ionosphere. Layer of the ionosphere that are filled with electrically charged atoms can reflect electromagnetic waves of low frequency (within a frequency spectrum of radio waves of medium) and used in radio transmissions.
Because of his energy and strong enough in character that can ionize the material, ultraviolet radiation, which is classified as hazardous to humans (particularly if emitted in large intensity). Fortunately, the Earth's atmosphere has a layer that can withstand and absorb ultraviolet radiation from the sun so that sunlight reaching the earth is in a harmless level. Of course you already know the layer that is? yes, the ozone layer.
ozone layer in the atmosphere to hold some ultraviolet radiation
Use of chemicals for cooling (refrigerators and air conditioning) or to the freon in the form of a spray (spray and perfume form pilok / spray paint), may cause leakage of the ozone layer. This causes the ultraviolet rays can penetrate the ozone layer and to the earth's surface, something that is very dangerous for humans. If more and more exposed to ultraviolet light onto the surface of the earth and of humans, adverse effects to humans and the environment can be incurred.
causing gas to spray the hole in the ozone layer
Skin cancer and vision problems, diseases such as cataracts can be caused from excessive ultraviolet radiation. Green algae as a source of natural food and the first chain in the food chain may decrease as a result of this ultraviolet radiation. This can disrupt the balance of nature and is something that is very harmful for the life of living creatures on Earth.
Ultraviolet rays can also be generated by internal processes of atoms and molecules. Ultraviolet rays can also be used in food sterilization process in which germs and harmful bacteria in food can be turned off.
X-ray
X-rays in medicine known as X-rays. Used to examine internal organs in the body. Fracture on the inside of the body can be seen using this X-ray.
X-rays are at 300 million GHz frequency range (10 ^ 17) and 50 billion GHz (10 ^ 19). The discovery of X-rays are considered as one of the important discoveries in physics. X-rays discovered by German physicist named Wilhelm Rontgen when he was studying cathode rays. The most common way to produce X-rays is through a mechanism called radiation bremstrahlung or deceleration. This mechanism is implemented by the X-ray the first time to produce X-rays. In the theory of electromagnetic wave radiation is known that electric charge is accelerated (or slowed) would produce electromagnetic waves. Furthermore through deceleration radiation, X-rays are also produced from the internal transition process of electrons in atoms or molecules.
photo results of X-ray irradiation
Gamma Rays
production of gamma rays by atomic nuclei
Gamma rays are electromagnetic waves having a frequency (and hence energy) is greatest. Gamma rays have a frequency range from 18 to 10 rank 10 rank 22 Hz. Gamma rays produced through the processes within the nucleus (nuclear).
Properties of Electromagnetic Waves
1. Can propagate in a vacuum.
2. Is a transverse wave propagation direction), so may be susceptible to(vibration direction polarization.
3. May experience reflection, refraction, interference and diffraction.
4. Not deflected in an electric field or magnetic field.
Note:
Radio waves are used as a carrier wave communication systems because it is easy being reflected by the layer of the ionosphere.
There are two kinds of ways to bring a sound wave:
1. Amplitude modulation (AM)
Amplitude of the radio wave frequency is adjusted by a sound wave with fixed frequency.
2. Frequency Modulation (FM)
Adjusted frequency radio waves with a frequency fixed-amplitude sound waves.
FM systems are superior to AM because FM can reduce the sound of many due to electricity in the air, although very limited scope.
