**Explain the laws of magnetic attraction and repulsion?**

A magnet attracts the north and south if the poles are poles repel THAT IF SHE POLE IS THE DIFFERENCE attract

**Magnetic Attraction**

**How do magnetic fields work in the most fundamental level?**

*What is the magnetic force? How can affect* the objects together, without physically touching as in the case of magnetic attraction (or repulsion)? I''m dying to understand that in most * * Level fundamental. Any ideas? I think the new M-surprising theory (also known as superstring theory) could resolve that question. M-theory suggests all * *, matter and force, consists of a single ingredient. An unimaginably small vibrating strands of energy called strings. In this context, the force is a string, so you can get a range of other chains (matter) and affect them. The problem is I do not know if these channels are physical entities, real or just a mathematical model helps us understand the reality? If M-theory is correct, and if these chains are real physical entities, then the issue is easily solved.

The difference between B and H are two quantities that physicists may refer to the magnetic field, symbolized vec {H} and vec {B}. Although the term "field Magnetic "was historically reserved for vec {H} with vec {B} is called" magnetic induction ", vec {B} is now understood as the most fundamental institution, and most modern writers refer to vec {B} as the magnetic field, except where the context does not clarify whether the amount in question is Vec {H} or vec {B}. See [2] The difference between mathbf {B} and mathbf {H} vector Maxwell goes back to 1855 document entitled "On Faraday''s lines of force. "He later clarified his concept of a sea of molecular vortices that appears in your document in 1861 in physical lines of force – 1861. In this context, vec {H} represented pure vorticity (spin), while mathbf {B} was a vorticity weight was weighted by the density of vortex sea. Maxwell considered magnetic permeability μ is a measure of the density of vortex sea. Therefore the relationship, (1) Magnetic induction current causes a magnetic current density Vec {B} = mu vec {H} was essentially a rotational analogy to the linear relationship of electrical current, (2) Electric convection Vec {J} = rho vec {v} where ρ is the density of electric charge. Vec {B} was seen as a kind of magnetic current of vortices aligned in their axial planes, with vec {H} is the circumferential speed of the vortices. The electric current equation can be seen as a convection current load power implies a linear movement. By analogy, the magnetic induction equation is a current twist. There is no linear movement of the inductive current along the direction mathbf {B} of vectors. The magnetic induction current represents lines of force. In particular, represents the lines of force of law the inverse of the square. The extension of the above considerations confirms that where vec {B} is vec {H}, where vec {J} is ρ, then it necessarily follows Gauss''s law and equation of continuity of the charge that mathbf {D} is vec {E}. Ie. Vec {B} parallels with mathbf {D}, while Vec {H} parallels with vec {E}. In SI units, vec {B} and vec {H} are measured in tesla (T) and amperes per meter (A / m), respectively, or cgs units, in gauss (G) and Oe (Oe), respectively. Two parallel wires carrying electrical current in the same direction will generate a magnetic field that will make an attractive force between them. This fact is used to define the value of a power amp. [Edit] Magnetic field of current flow of charged particles current (I) flowing through a wire produces a magnetic field () around the cable. The field is oriented according to the rule of the right hand grip. Current (I) flowing through a wire produces a magnetic field ( vec {B}) around the cable. The field is oriented according to the rule of the right hand grip. Drifts of charged particles in a homogeneous magnetic field. (A) No disturbing force (B) With an electric field, E (C) With an independent force, F (eg gravity) (D) inhomgeneous In a magnetic field, H graduate charged particle moving in a homogeneous magnetic field. (A) No disturbing force (B) With an electric field, E (C) With an independent force, F (eg gravity) (D) In a magnetic field inhomgeneous graduate H substitution in the definition magnetic field vec {B} = vec {v} times frac {1} {c ^ 2} vec {E} the electric field proper-like point charge (see Coulomb''s law) vec {E} = {1 over 4 pi epsilon_0} {q over r ^ 2} hat {r} = {10 ^ {-7}} {c ^ 2} {Q over {r} ^ 2} hat {r} results in magnetic field equation of charge motion, which is usually called the Biot-Savart law: vec {B} = Vec {v} times frac { mu_0} {4 pi} frac {q} {r ^ 2} hat {r} where q is the electric charge, whose motion generates the magnetic field, measured in coulombs vec {v} is the speed of the electric charge q that is generating vec {B}, measured in meters per second vec {B} is the magnetic field (measured in Tesla) [edit] Lorentz force in the wire segment Integration Lorentz force on a charged particle flow on a single (current) of charged particles results in the Lorentz force on a fixed wire carrying electric current: F = I l times B , where F = force measured in newtons I = current measured in amperes B = magnetic field measured in tesla times wire cross product = vector l = cable length measured in meters in the equation above, the current vector I is a vector with magnitude equal to the current scale, I, and the direction pointing along the wire in which current is flowing. Alternatively, instead of current, the wire segment l can be considered a vector. The Lorentz force in a macroscopic current-carrying is often referred to as the Laplace force. [Edit] Properties [edit] Magnetic field lines Magnetic field lines shown by iron filings lines magnetic field shown by iron filings direction of magnetic field vector from the above definition. Coincides with the direction of orientation of a magnetic dipole, like a little magnet, a small current loop in magnetic field, or a group of small particles of ferromagnetic material (See figure). [Edit] See also Polo labeling confusion magnetic North Pole and South Magnetic Pole. The end of the needle of a compass points north was historically called the "north" magnetic pole of the needle. Since dipoles are vectors and align "head to tail" with each other, the magnetic pole located near the geographic North Pole is actually the "south" pole. The "north" and "south" poles of a magnet or a magnetic dipole are labeled similarly to the north and south poles of the compass. Near the north pole of a bar or cylinder magnet, the magnetic field vector is directed out of magnet, near the south pole in the magnet. This magnetic field continues inside the magnet (for no real "poles" anywhere inside or outside of a magnet where the field stops or starts). Breaking a magnet in half does not separate the poles but produces two magnets with two poles of each magnetic field. is probably produced by electric currents in its liquid core equation. It may be easier to explain if you work backwards from the: B = frac {F} {IL} , where B is the magnitude of the flux density is measured in tesla SI and F is the force experienced by a wire, is measured in Newtons, I is current, as amp L is the length of the cable, measured in meters demonstration that demonstration is Fleming''s hand rule Fleming''s left hand rule for magnetic flux density tesla is equal to 1, a force of 1 newton must act in a cable length of one meter has a power amp. 1 newton of force is not easily achieved. For example, the electromagnets superconductors most powerful in the world have flux densities of ''only'' 20 T. This is the case, obviously, for both natural magnets and electromagnets, but a magnetic field can only act in cargo movement – hence the current, which, in the equation as well. The equation can be adjusted to incorporate a single movement load, ie, protons, electrons, and via BQv F = , where Q is the charge in coulombs, v is the velocity of that charge in meters per second. Fleming''s left hand rule for the movement, flow and the polarity can be used to determine the direction of any of the other two, as shown in the example. You can also remember as follows. The digits of the second thumb to indicate "the Force", "B-field" and "I (now)" respectively, or FBI in a word. For professional use, the right-hand rule is used instead hold its origin in the definition of vector product in the right-handed system of coordinates. Other units of magnetic flux density is a Gauss = 4.10 Tesla = 100 microteslas (that value) 1 gamma = 10-9 = 1 nanotesla Tesla (NT) [edit] Rotation magnetic fields Main article: The rotating magnetic field generator is a key principle in the operation of AC motors. A permanent magnet in this field will rotate to maintain its alignment with the external field. This effect was conceived by Nikola Tesla, and later used in his, and others, early AC ( AC) electric motors. A rotating magnetic field can be constructed with two orthogonal coils with phase difference of 90 degrees in the AC current. However, in practice this system is supplied through a three-wire with unequal currents. This inequality would cause serious problems in standardization of driver size and thus to overcome it, three-phase systems that allow the three currents are equal in magnitude and 120 degrees phase difference. Three similar coils having mutual geometrical angles of 120 degrees to create the rotating magnetic field in this case. The capacity of the system of three phases to create a rotating field, used electric motors, is one of the main reasons why three-phase systems dominate the world power system power supply. Because magnets degrade with time, synchronous motors and induction motors use short-circuited rotors (instead of a magnet) following the rotating magnetic field of a stator Multicoil. The short circuit turns the rotor develop eddy currents in the stator rotating field and the currents of these in turn move the rotor by the Lorentz force. In 1882, Nikola Tesla identified the concept of rotating magnetic field. In 1885, Galileo Ferraris independently researched the concept. In 1888, Tesla received U.S. Patent 968 381 for their work. Also in 1888, Ferraris published his research in a paper to the Royal Academy of Sciences of Turin. [Edit] Main article Hall effect: Effect Hall Due to the Lorentz force is charge sign-dependent (see above), the result is a separation of charges when a current-carrying conductor is placed in a transverse magnetic field, with a buildup of opposite charges on two opposite sides of the conductor in the direction normal to the magnetic field and the potential difference between these parts can be measure. The Hall effect is often used to measure the magnitude of a magnetic field, and to find the sign of dominant charge carriers in semiconductors (electrons negative or positive holes). [Edit] Extension of the Theory of Relativity Einstein said in 1905 that a magnetic field is the relativistic part of an electric field. [3] appears as a mathematical product of Lorentz coordinate transformation of electric field of a reference system to another (usually from the co-movement with moving reference frame to load the reference system of the observer who does not move). (However, the Lorentz transformation can not be applied to electric fields unless it already presupposes the existence of magnetic fields and their interaction with electric fields in terms of Maxwell equations. As such, the magnetic field can be considered as a byproduct of the Lorentz transformation.) When an electric charge moves from the perspective of an observer, the electric field of this charge because space contraction is no longer seen by the observer as time dilation with spherical symmetry, due to the non-radial, and it must be calculated using Lorentz transformations. One product of these transformations is the electric field that acts only on charges in motion – and we call the "field magnetic ". It is a manifestation of the relativistic critical electric field. A magnetic field can be caused by another moving charge (ie by an electric current) or a changing electric field. The magnetic field is a vector quantity and has SI units of tesla, 1 T = 1 kg · s-2 · A-1. An equivalent, but older, the Tesla is a unit Weber/m2.-El quantum mechanical motion of electrons in atoms produces the magnetic fields of permanent ferromagnets. Spinning charged particles also have magnetic moment. Some electrically neutral particles (like the neutron) with non-zero spin also have magnetic time due to the charge distribution in their internal structure. Particles with zero spin have no magnetic moment is the result of a magnetic field is the result of moving electric field. A magnetic field is a vector field, is associated with each point in space a (pseudo) vector that can vary over time. The field direction is the direction of equilibrium of a magnetic dipole (like a compass needle) placed in the field. The Lorentz transformation of a spherically symmetric electric E-field characteristic of a moving electrical charge (eg, the electric field of an electron moving in a wire) system load reference to the reference of an observer does not move result in the following term that can define or label as "magnetic field." Maxwell did much to unify static electricity and magnetism, producing a set of four equations relating the two fields. However, in the formulation of Maxwell, there were still two different fields to describe different phenomena. It was Albert Einstein who showed, using special relativity, that electric fields and magnetism are two aspects of the same thing (a rank-2 tensor), and that an observer at rest can feel a magnetic force that moves an observer sees only a electrostatic force. Therefore, using special relativity, magnetic forces are a manifestation of electrostatic forces of charges in motion and can be predicted from knowledge of the electrostatic forces and velocity (relative to some observers) of the charges. A thought experiment can do to show this is with two identical infinite and parallel lines of charge are not moving relative to each other, but they move together on to an observer. Another observer is moving alongside the two load lines (at the same speed) and observes only electrostatic repulsive force and acceleration. The first or "stationary" observer see the two lines (and second observer) moving past with some known velocity also observes that Watch the "movement" observer stops slower (due to time dilation) and thus indicates the repulsive acceleration lines load more slowly than the "moving" observer sees. The reduction of repulsive acceleration can be thought of as an attractive force added in the context of classical electrodynamics, which reduces the electrostatic repulsion and increases in magnitude with increasing speed. This pseudo-force is exactly the same as the electromagnetic force in a classical context. A changing magnetic field is mathematically the same as a moving magnetic field (see relativity movement). Thus, according to the equations of Einstein field transformation (ie, the Lorentz transformation of field of a suitable framework to reference system does not move), some of it manifests as a component of the electric field. This is known as Faraday''s law of induction and is the principle behind electric generators and electric motors -. [Edit] General Electric * field effect produced by an electric charge that exerts a force on charged objects in its surroundings -. * field electromagnetic field composed of two partners, the electric vector fields and the magnetic field. field of a * Electromagnetism – Physics of the electromagnetic field: field, encompassing all of space, composed of electric and magnetic field. * Country of Magnetism – phenomenon by which materials exert attractive or repulsive force on other materials – *. Magnetohydrodynamics academic discipline that studies the dynamics of electrically conducting fluids. * The magnetic monopole magnetic flux * * SI electromagnetism units