What is the difference between magnetism and eletromagnetism?
603148
Magnetism is an inherent property of a material or object, e.g. the earth.\n\nElectromagnetism is magnetism created by an electrical field - electromagnet - and these can be found all over the place - electrical relays, doorbells (check yours you will almost certainly find that it contains an electromagnet, etc.\n\nIn most cases when the current is turned off the electromagnetism goes.  However, it is possible to magnetise something permanently by use of electromagnetism.
65053
Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, which exerts a force on those particles that possess the property of electric charge, and is in turn affected by the presence and motion of such particles. The term electrodynamics is sometimes used to refer to the combination of electromagnetism with mechanics, and deals with the effects of the electromagnetic field on the dynamic behavior of electrically charged particles. Electromagnetism encompasses various real-world electromagnetic phenomena.\n\n\nIt is often convenient to understand the electromagnetic field in terms of two separate fields: the electric field and the magnetic field. A non-zero electric field is produced by the presence of electrically charged particles, and gives rise to the electric force; this is the force that causes static electricity and drives the flow of electric charge (electric current) in electrical conductors. The magnetic field, on the other hand, can be produced by the motion of electric charges, or electric current, and gives rise to the magnetic force associated with magnets.\n\nThe term "electromagnetism" comes from the fact that the electric and magnetic fields generally cannot be described independently of one another. A changing magnetic field produces an electric field (this is the phenomenon of electromagnetic induction, which underlies the operation of electrical generators, induction motors, and transformers). Similarly, a changing electric field generates a magnetic field.\n\nBecause of this interdependence of the electric and magnetic fields, it makes sense to consider them as a single, theoretically coherent entity — the electromagnetic field. This unification, which was completed by James Clerk Maxwell, is one of the triumphs of 19th century physics. It had far-reaching consequences, one of which was the elucidation of the nature of light: as it turns out, what we think of as "light" is actually a propagating oscillatory disturbance in the electromagnetic field, i.e., an electromagnetic wave. Different frequencies of oscillation give rise to the different forms of electromagnetic radiation, from radio waves at the lowest frequencies, to visible light at intermediate frequencies, to gamma rays at the highest frequencies.\n\nThe theoretical implications of electromagnetism led to the development of special relativity by Albert Einstein in 1905.\n\nedit SI electromagnetism units \nSymbol Name of Quantity Derived Units  Base Units \nI Current ampere (SI base unit) A A \nq Electric charge, Quantity of electricity coulomb C A·s \nV Potential difference volt V J/C = kg·m2·s−3·A−1 \nR, Z Resistance, Impedance, Reactance ohm Ω V/A = kg·m2·s−3·A−2 \nρ Resistivity ohm metre Ω·m kg·m3·s−3·A−2 \nP Power, Electrical watt W V·A = kg·m2·s−3 \nC Capacitance farad F C/V = kg−1·m−2·A2·s4 \n Elastance reciprocal farad F−1 V/C = kg·m2·A−2·s−4 \nε Permittivity farad per metre F/m kg−1·m−3·A2·s4 \nχe Electric susceptibility (dimensionless) - - \n Conductance, Admittance, Susceptance siemens S Ω−1 = kg−1·m−2·s3·A2 \nσ Conductivity siemens per metre S/m kg−1·m−3·s3·A2 \nH Magnetic field, magnetic field intensity ampere per metre A/m A·m−1 \nΦm Magnetic flux weber Wb V·s = kg·m2·s−2·A−1 \nB Magnetic flux density, magnetic induction, magnetic field strength tesla T Wb/m2 = kg·s−2·A−1 \n Reluctance ampere-turns per weber A/Wb kg−1·m−2·s2·A2 \nL Inductance henry H Wb/A = V·s/A = kg·m2·s−2·A−2 \nμ Permeability henry per metre H/m kg·m·s−2·A−2 \nχm Magnetic susceptibility (dimensionless) - -
512643
ferromagnet materials will lose their magnetism if heated above a point known as the Curie temperature. \nExposure to an opposing magnetic field will "knock it down", but not demagnetize it completely.
542625
It's either just one charge: The electrical, which appears in positive and negative characteristics, or if you see "charge" in a more general way it's more then one charge: magnetism has also a source, but that appears always in dipoles, mass is the "charge" of gravity, but that appears just with a positive sign, and the strong interaction has three kind of charges, called "colour charges": red green and blue.\n\nTwo see an underlaying principle for this "chaos" we need the "Grand Unified Theory" which still is "work in progress" ;)
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
30487
Well even though humans have known about magnets for thousands of years, the real reason they work is still somewhat mysterious. Depending on how deep you want to investigate, it can be a very complicated phenomenon. \n\nA magnet is, at its foundation, caused by the movement of electrical charge (yes this is the Biot-Savart Law). When charges (like electrons for example) move, they produce magnetic fields. If a charge moves in a loop, it creates a magnetic field. The magnetic field can be basically represented by an invisible set of arrows in space, that point in a direction. In the case of the loop, the arrows of the magnetic field will point out of the loop for a positive charge moving counter clockwise (this is the so-called "right hand rule"), and into the loop for a charge moving clockwise (some pictures are in the reference attached). \n\nThe magnetic field has a "north" end and a "south end". The little arrows from our moving charge are pointing in the "north" magnetic direction, and away from the "south" magnetic direction. It is a mysterious and interesting property of electromagnetism that two objects with fields that oppose each other, i.e., the little arrows of the field do not line up, so either the north end of one field is facing the north end of the other field, or the two south ends are facing each other, repel, or resist movement of the two objects towards each other with some force. \n\nOn the other hand, if the little arrows line up, the two objects attract each other with some force. \n\nThe little arrows are aligned along the so-called "magnetic lines of force". \n\nThe forces that result from magnetic fields (and for that matter, electric fields) are fundamental forces, and part of the four fundamental forces of the universe (strong, weak, electromagnetic and gravity). It is believed that these forces are caused, at their base, by particles passing "messenger particles" back and forth. In the case of electromagnetism, the messenger particle is a photon. How this actually works is still somewhat poorly understood, and is involved with the world of quantum mechanics, which is very counterintuitive but interesting. \n\nHowever, what is important is that we understand it well enough to make models of magnetism, and to make predictions based on those models which we can verify and use. All of electricity and electric motors are based on our ability to design systems with magnets and to be able to build and use them.
166771
You have confused 2 different techniques I suspect. \n\nMagnetotelluric methods use EM fields to probe the interior of the earth. Seismic methods use mechanical waves, a different technique.
7670
Hi, Mimi.   I found 2 definitions, one short and one longer, so I included them both.  Hope it helps!\n\nSHORT DEFINITION:\n\nIt is a phenomenon exhibited by materials like iron (nickel or cobalt) that become magnetized in a magnetic field and retain their magnetism when the field is removed.\n\n\nLONGER DEFINITION:\n\n\nFerromagnetism is a phenomenon by which a material can exhibit a spontaneous magnetization, and is one of the strongest forms of magnetism. It is responsible for most of the magnetic behavior encountered in everyday life and, along with ferrimagnetism, is the basis for all permanent magnets (as well as the metals that are noticeably attracted to them).
983278
The electrostatic force is one of the four fundamental forces. It acts between all charged particles, repulsive between like charges and attractive between unalike charges. Going a bit deeper its origin is in the exchange of carrier particles, which in the case of the electrostatic force are photons.\n\nMagnetism is an effect of special relativity on the electrostatic force. Hence it only applies between moving charges. An electron will have no response to a magnetic field if it is not moving and the field is not changing. Otherwise it will move perpendicular to both its path and the magnetic field.
139513
Metals are attracted to magnets due to unbonded electron pairs that can be easily influenced by a magnetic field.\nFerrous metals (refering to Iron) can be easily influenced by a magnetic field, making them very magnetic.
1097908
Iron, cobalt and nickel can be magnetic. They can be made to have polarity. Poles that are alike repel and poles which are not alike attract. A magnet will attract all of them if they are not polarized. If they are polarized, a magnet will attract or repel according to the polarity.\n;-D
669781
Magnetic property of a material is due to the arrangement of Domains in it. If you are not of science background, simply think it as it is the arrangement of atoms of the material, which is responsible for its magnetism. If you provide a permanent magnet with electric supply, the arrangement of atoms in it will be disturbed resulting in loss or decrease in its magnetism.\nNot only the electric supply, but heating or even strong jerks can also lead to the disturbed atomic arrangement and therefore decreased or completely lost magnetism.
886336
Different metals have different magnetic field strengths.\n\nFor example, neodymium magnets are among the strongest.
797944
in order to be ferro magnetic a material must contain ferrous or translated from latin - Iron.  If it doesn't have iron then it can't be ferro-magnetic.  Iron is magnetic because of the fact that it has one valence electron in its outer orbit and is a metal.
1161789
IT could be diamagnetic according to electron configuration from Chemistry. But without specific formula I would say your best bet is e nomagnetic.
31611
Well even though humans have known about magnets for thousands of years, the real reason they work is still somewhat mysterious. Depending on how deep you want to investigate, it can be a very complicated phenomenon. \n\nA magnet is, at its foundation, caused by the movement of electrical charge (yes this is the Biot-Savart Law). When charges (like electrons for example) move, they produce magnetic fields. If a charge moves in a loop, it creates a magnetic field. The magnetic field can be basically represented by an invisible set of arrows in space, that point in a direction. In the case of the loop, the arrows of the magnetic field will point out of the loop for a positive charge moving counter clockwise (this is the so-called "right hand rule"), and into the loop for a charge moving clockwise (some pictures are in the reference attached). \n\nThe magnetic field has a "north" end and a "south end". The little arrows from our moving charge are pointing in the "north" magnetic direction, and away from the "south" magnetic direction. It is a mysterious and interesting property of electromagnetism that two objects with fields that oppose each other, i.e., the little arrows of the field do not line up, so either the north end of one field is facing the north end of the other field, or the two south ends are facing each other, repel, or resist movement of the two objects towards each other with some force. \n\nOn the other hand, if the little arrows line up, the two objects attract each other with some force. \n\nThe forces that result from magnetic fields (and for that matter, electric fields) are fundamental forces, and part of the four fundamental forces of the universe (strong, weak, electromagnetic and gravity).  It is believed that these forces are caused, at their base, by particles passing "messenger particles" back and forth. In the case of electromagnetism, the messenger particle is a photon. How this actually works is still somewhat poorly understood, and is involved with the world of quantum mechanics, which is very counterintuitive but interesting. \n\nHowever, what is important is that we understand it well enough to make models of magnetism, and to make predictions based on those models which we can verify and use. All of electricity and electric motors are based on our ability to design systems with magnets and to be able to build and use them.
304336
No there is no substance which can block magnetism except another magnet.  You can block electromagnetic energy quite easily depending on the strength.