Electromagnetism
Electricity · Magnetism
Electrostatics
Electric charge
Coulomb's law
Electric field
Gauss's law
Electric potential
Electric dipole moment
Magnetostatics
Ampère's law
Magnetic field
Magnetic flux
Biot-Savart law
Magnetic dipole moment
Electrodynamics
Electric current
Lorentz force law
Electromotive force
(EM) Electromagnetic induction
Faraday-Lenz law
Displacement current
Maxwell's equations
(EMF) Electromagnetic field
(EM) Electromagnetic radiation
Electrical Network
Electrical conduction
Electrical resistance
Capacitance
Inductance
Impedance
Resonant cavities
Waveguides
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Magnetostatics is the study of static magnetic fields. In electrostatics, the charges are stationary, whereas here, the currents are stationary. As it turns out magnetostatics is a good approximation even when the currents are not static as long as the currents do not alternate rapidly. Image File history File links Solenoid. ... Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... Lightning strikes during a night-time thunderstorm. ... It has been suggested that this article or section be merged with magnet. ... Electrostatics (also known as Static Electricity) is the branch of physics that deals with the forces exerted by a static (i. ... Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. ... Coulombs torsion balance In physics, Coulombs law is an inverse-square law indicating the magnitude and direction of electrostatic force that one stationary, electrically charged object of small dimensions (ideally, a point source) exerts on another. ... It has been suggested that optical field be merged into this article or section. ... In physics and mathematical analysis, Gausss law is the electrostatic application of the generalized Gausss theorem giving the equivalence relation between any flux, e. ... This article or section does not cite any references or sources. ... In physics, the electric dipole moment for a pair of opposite charges of magnitude q is defined as the magnitude of the charge times the distance between them and the defined direction is toward the positive charge. ... An electric current produces a magnetic field. ... In physics, a magnetic field is an axial vector field that traces out solenoidal lines of force in and around closed electric circuits and bar magnets. ... Magnetic flux, represented by the Greek letter Φ known as phi, is a measure of quantity of magnetism, taking account of the strength and the extent of a magnetic field. ... The Biot-Savart law is a physical law with applications in both electromagnetics and fluid dynamics. ... A bar magnet. ... Classical electrodynamics (or classical electromagnetism) is a theory of electromagnetism that was developed over the course of the 19th century, most prominently by James Clerk Maxwell. ... Electric current is the flow (movement) of electric charge. ... In physics, the Lorentz force is the force exerted on a charged particle in an electromagnetic field. ... Electromotive force (emf) is the amount of energy gained per unit charge that passes through a device in the opposite direction to the electric field existing across that device. ... Electromagnetic induction is the production of an electrical potential difference (or voltage) across a conductor situated in a changing magnetic flux. ... Faradays law of induction (more generally, the law of electromagnetic induction) states that the induced emf (electromotive force) in a closed loop equals the negative of the time rate of change of magnetic flux through the loop. ... Displacement current is a quantity related to a changing electric field. ... In electromagnetism, Maxwells equations are a set of equations first presented as a distinct group in the later half of the nineteenth century by James Clerk Maxwell. ... The electromagnetic field is a physical field that is produced by electrically charged objects and which affects the behaviour of charged objects in the vicinity of the field. ... It has been suggested that this article or section be merged with light. ... This article or section does not adequately cite its references or sources. ... Electrical conduction is the movement of electrically charged particles through a transmission medium (electrical conductor). ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ... Capacitance is a measure of the amount of electric charge stored (or separated) for a given electric potential. ... Inductance (or electric inductance) is a measure of the amount of magnetic flux produced for a given electric current. ... Electrical impedance, or simply impedance, is a measure of opposition to a sinusoidal alternating electric current. ... A resonator is a device or part that vibrates (or oscillates) with waves. ... It has been suggested that this article or section be merged with Waveguide (optics). ... In physics, a magnetic field is an axial vector field that traces out solenoidal lines of force in and around closed electric circuits and bar magnets. ... Electrostatics is the branch of physics that deals with the force exerted by a static (i. ... In electricity, current refers to electric current, which is the flow of electric charge. ...

Applications

Magnetostatics as a special case of Maxwell's equations

Starting from Maxwell's equations, the following simplifications can be made: In electromagnetism, Maxwells equations are a set of equations first presented as a distinct group in the later half of the nineteenth century by James Clerk Maxwell. ...

• ignore any electrostatic charge
• ignore the electric field
• presume the magnetic field is constant with respect to time

Name	Partial differential form	Integral form
presumption
Gauss's law for magnetism:
presumption
Ampère's law:

The quality of this approximation may be guessed by comparing the above equations with the full version of Maxwell's equations and considering the importance of the terms that have been removed. Of particular significance is the comparison of the term against the term. If the term is substantially larger, then the smaller term may be ignored without significant loss of accuracy. In mathematics, a partial differential equation (PDE) is a relation involving an unknown function of several independent variables and its partial derivatives with respect to those variables. ... In calculus, the integral of a function is an extension of the concept of a sum. ... In physics and mathematical analysis, Gausss law is the electrostatic application of the generalized Gausss theorem giving the equivalence relation between any flux, e. ... An electric current produces a magnetic field. ... In electromagnetism, Maxwells equations are a set of equations first presented as a distinct group in the later half of the nineteenth century by James Clerk Maxwell. ...

Re-introducing Faraday's law

A common technique is to solve a series of magnetostatic problems at incremental time steps and then use these solutions to approximate the term . Plugging this result into Faraday's Law finds a value for (which had previously been ignored). This method is not a true solution of Maxwell's equations but can provide a good approximation for slowly changing fields. Faradays law can mean: Faradays law of induction (electromagnetic fields) Faradays law of electrolysis Category: ... In electromagnetism, Maxwells equations are a set of equations first presented as a distinct group in the later half of the nineteenth century by James Clerk Maxwell. ...

Solving magnetostatic problems

If all currents in a system are known (i.e. if a complete description of is available) then the magnetic field can be determined from the currents by the Biot-Savart equation: The Biot-Savart law is a physical law with applications in both electromagnetics and fluid dynamics. ...

This technique works well for problems where the medium is a vacuum or air or some similar material with a relative permeability of 1. This includes Air core inductors and Air core transformers. One advantage of this technique is that a complex coil geometry can be integrated in sections, or for a very difficult geometry numerical integration may be used. Since this equation is primarily used to solve linear problems, the complete answer will be a sum of the integral of each component section. Look up Vacuum in Wiktionary, the free dictionary. ... Layers of Atmosphere (NOAA) Air redirects here. ... In electromagnetism, permeability is the degree of magnetization of a material that responds linearly to an applied magnetic field. ... Numerical Integration with the Monte Carlo method: Nodes are random equally distributed. ... The word linear comes from the Latin word linearis, which means created by lines. ...

One pitfall in the use of the Biot-Savart equation is that it does not implicitly enforce Gauss's law for magnetism so it is possible to come up with an answer that includes magnetic monopoles. This will occur if some section of the current path has not been included in the integral (implying that electrons are being continuously created in one place and destroyed in another). In physics, a magnetic monopole is a hypothetical particle that may be loosely described as a magnet with only one pole (see electromagnetic theory for more on magnetic poles). ... e- redirects here. ...

Using Biot-Savart in the presence of Ferromagnetic, Ferrimagnetic or Paramagnetic materials is difficult because the external current induces a surface current in the magnetic material which in turn must be included in the integral. The value of the surface current depends on the magnetic field which was what you were trying to calculate in the first place. For these problems, using Ampère's law (usually in integral form) is a better choice. For problems where the dominant magnetic material is a highly permeable magnetic core with relatively small air gaps, a magnetic circuit approach is useful. When the air gaps are large in comparison to the magnetic circuit length, fringing becomes significant and usually requires a finite element calculation. The finite element calculation uses a modified form of the magnetostatic equations above in order to calculate magnetic potential. The value of can be found from the magnetic potential. Ferromagnetism is a phenomenon by which a material can exhibit a spontaneous magnetization, and is one of the strongest forms of magnetism. ... A ferrimagnetic interaction is a specific type of antiferromagnetic interaction in which the net spin of the system is not equal to zero due to the spin in each direction not being equal, and therefore not cancelling. ... Paramagnetism is the tendency of the atomic magnetic dipoles, due to quantum-mechanical spin, in a material that is otherwise non-magnetic to align with an external magnetic field. ... An electric current produces a magnetic field. ... A magnetic core is the core of an electromagnet or inductor. ... A magnetic circuit is a closed path containing a magnetic flux. ... A magnetic circuit is a closed path containing a magnetic flux. ... Finite element analysis (FEA) or finite element method (FEM) is a numerical technique for solution of boundary-value problems. ... Finite element analysis (FEA) or finite element method (FEM) is a numerical technique for solution of boundary-value problems. ... In physics, the magnetic potential is a method of representing the magnetic field by using a potential value instead of the actual vector field. ... In physics, the magnetic potential is a method of representing the magnetic field by using a potential value instead of the actual vector field. ...