hello...Can u describe your understanding about role of elektromagnetic play in science and technology..?
102674
Electromagnetism is the what allows information contained in electric circuits to actually leave the circuits. Althought he technique by which the information (electric signal) actually leaves the circuit is quite complicated, suffice it to say, that using an antenna, this information can be allowed to travel through air.\nCo-incidentally, even light happens to be an electromagntetic wave. So, you can say that human beings owe their vision to electromagnetism.\n\nMircowaves - an electromagnetic phenomenon allow you to exhange information with satellites, besides of course, allowing you to cook food.\n\nThink about it! Radio, Mobile phone communication etc. all owes its existence to electromagnetism.\n\nThis is course is with respect to electromagnetic wave phenomeona. When you actually think about the fact that one can create artificial magnetics using electric current, the possibilities are limitless
1048978
Doubtul.  The earth's magnetic field simply isn't that strong.  If it were, it would overwhelm any electronic devices on earth due to induced current.  While overall it's strong enough to protect us from harm from the solar wind and other nasty charged particles in space, it's not strong enough to harness locally for any useful work.
141111
Its like a microwave for metals, only kilohertz instead of gigahertz.  Its done with a coil instead of a magnetron.
1173860
http://www.oz.net/~coilgun/theory/solenoidphysics.htm
35844
Log on to http://en.wikipedia.org/wiki/Magnet\n\nand check out Characteristics of magnetic materials
775698
An electron, with its negative charge, is surrounded by an electromagnetic field. Normally, in most materials, this field is canceled out by the random positioning of all of the other electrons in the material. \n\nIf these electrons are aligned, the material will become a magnet with the magnetic fields aligned toward one end of the material.\n\nIf the electrons are traveling through the material (current or electrical flow) the magnetic field will be moving with the electrons and will surround the wire (refer to "right hand rule") \nIf the wire is coiled around a piece of iron, for instance, this magnetic field will become very strong and align the electrons in the iron - thus magnetizing the iron.
193770
Electro-magnetic radiation is a carrier of electro-magnetic energy by transmitting the oscillation of the electro-magnetic field through space or matter. The transmission of electro-magnetic radiation is derived from the Maxwell equations. Electro-magnetic radiation has the characteristics of both wave motion and particle motion. \n\n(1) Characteristics as wave motion \nElectro-magnetic radiation can be considered as a transverse wave with an electric field and a magnetic field. A plane wave for an example as shown in Figure 1.2.1 has its electric field and magnetic field in the perpendicular plane to the transmission direction. The two fields are located at right angles to each other. The wavelength L  , frequency F and the velocity V have the following relation. V = L/F\n\nElectro-magnetic radiation is transmitted in a vacuum of free space with the velocity of light c, ( = 2.998 x 108 m/sec) and in the atmosphere with a reduced but similar velocity to that in a vacuum. The frequency n is expressed as a unit of hertz (Hz), that is the number of waves which are transmitted in a second.\n\n(2) Characteristics as particle motion\nElectro-magnetic can be treated as a photon or a light quantum. The energy E is expressed as follow.\nE = h \nwhere h : Plank's constant\n : frequency \n\nThe photoelectric effect can be explained by considering the electro-magnetic radiation as composed of particles. Electro-magnetic radiation has four elements of frequency (or wavelength), transmission direction, amplitude and plane of polarization. The amplitude is the magnitude of oscillating electric field. The square of the amplitude is proportional to the energy transmitted by electro-magnetic radiation. The energy radiated from an object is called radiant energy. A plane including electric field is called a plane of polarization. When the plane of polarization forms a uniform plane, it is called linear polarization. \n\nThe four elements of electro-magnetic radiation are related to different information content as shown in Figure 1.2.2. Frequency (or wavelength) corresponds to the color of an object in the visible region which is given by a unique characteristic curve relating the wavelength and the radiant energy. In the microwave region, information about objects is obtained using the Doppler shift effect in frequency, that is generated by a relative motion between an object and a platform. The spatial location and shape of objects are given by the linearity of the transmission direction, as well as by the amplitude. The plane of polarization is influenced by the geometric shape of objects in the case of reflection or scattering in the microwave region. In the case of radar, horizontal polarization and vertical polarization have different responses on a radar image.\n\nAny wave function can be defined in terms of amplitude, A, and wave-length,  or frequency, v . A full description of such a wave also requires definition of a phase, phi . A simple one-dimensional wave-function, f(x), specifies the height of the wave at any horizontal point x where x is defined in terms of wavelength such that x=1=. This wave function could be represented as either a sine or a cosine function as follows: \n\nf(x)= Acos2pi(vx+o)
347377
At the very basics it has to do with magnetic fields. When a conductor (ie copper wire) is move across (perpendicular to) a magnet-ic field it causes the electrons in the copper wire to move\n\nthis is very basic info and their are other ways like solar cells (due to electron excitment in a different manner)
641079
I believe that to reverse the polarity of and electromagnet you need to reverse the eletric current becarse the move ment of eletrons makes magnets
1051252
Electrons are outside the nucleus of an atom and spin-random.Electrons are negative. [All matter has electrons (for the sake of agument)]\n\nMagnets-the 2 poles-electrons spinning in one direction at one end and the other direction at the other end.Positve and negative.\n\nElectricity-electrons travelling along a wire from the source like a chain reaction bumping the electron to electron ( current) to its final destination.\n\nMedical (diagnositc) xray production-a low voltage current is applied inside the xray machine-which causes the loss of electrons off a wire, these "free electons"(in a vacuum)negatively charged then travel high speed across inside the vacuum tube to a positive "plate". When the electrons hit this plate, their energy ends with the release of an x-ray.\n \nAn MRI (Magnet Resonance Imaging)of a person-a powerful magnet lines up the electrons of a persons body. When the magnet is turned off-the release of the electrons to again begin their spinning releases an xray from the persons's body.\n\nElectomagnet-a magnet wound with coil which when current is applied increases the magnetism. Example of how junk cars are picked up -electric current running around the magnet, magnet picks up car,car is moved to the top of the heap and the current turned off-boom-no more magnet-car drops.\n\nYou can make a magnet with electricity and electricity with a magnet.\n\nElectronics involve use of electrons. Remember they are free spinning little boogers. \n\nMagnets temporarily interfere with the spin of the electrons.
743760
1.a) receives the alternating current. \n b) the magnetic properties are altered by the electromagnetic field. . \nc) by the alterations in the core induces other alternating current in this coil. \n2.a) because the alternating current induces the varying magnetic field.\nb) that magnetic flux is passed by the core to the secondary coil.\nc) yes an alternating one. \n\nBecause radioactivity destroy organic tissues.
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According to Maxwell's laws, one type of field can induce the other and vice versa. This makes electromagnetic waves possible.
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Ok, i am an electronics teacher, but it will be very lengthy and cumbersome to explain, because you have to go as deep as electrons and positive and negative charges, so i can advise you to go to www.wikipedia.com and you will find a satisfactory answer.
641267
One use is superconductor research.\n\nhttp://www.iitap.iastate.edu/htcu/backissues/95APR01EM.TXT.html
141754
Electromagnetic waves??? thats something ive never heard of before. how about posting the article or the website online? \n\ni do know that electricity can be "transmitted" by magnetism, via electromagnetic induction. according to faraday's law, a changing rate of magnetic flux linkage induces an electromotive force, and thus induces current on a conductor. check out faraday's law at wikipedia for more info dude...
607179
a belt is driven across a surface rubbing the two together to make 'static', which is basically just free electrons. they collect in the big metallic ball, and when the potential is high enough between the ball and another conductor (or a conductor is brough close enough), the electrons 'jump the gap' to get to ground, and you see the big spark!\n\nWant to build one? Here's how:
1135256
Conduction?  I'm not aware of magnets having such a property.