, the magnetic flux traversing S is zero. The flux linkage of the coil is the product of the flux density, Magnetic flux - English - Sinhala Online Dictionary. What is Magnetic Flux A given smooth surface S with normal n is a flux surface of a smooth vector field B when $ \vec B \cdot \vec n = 0 $ everywhere on S. Special Thanks to all Sinhala Dictionarys including Malalasekara, Kapruka, MaduraOnline, Trilingualdictionary. In this study, the direction of a magnet that can be oriented along the 3 axes of X, Y, and Z is expressed by 3 bit variables, and the magnetic flux density generated is formulated using the variable and Bio-Savart's law, one of the laws of electromagnetism, and an objective function (function whose value should be maximized) as a combinatorial optimization problem in which the magnetic flux Researchers have discovered 'magnetic portals' forming high above Earth that can briefly connect our planet to the Sun. An MRI term for the magnetic lines of force (flux) which extend from a north polarity and enter a south polarity of a magnet to form a closed loop around the outside of a magnetic material. between the poles of a horseshoe magnet), the magnetic flux Φ through a certain area A which runs vertically to the flux can be calculated as follows: In physics, specifically electromagnetism, the magnetic flux (often denoted Φ or Φ B) through a surface is the surface integral of the normal component of the magnetic field flux density B passing through that surface. Magnetic Flux Density. It is analogous to electric current, I in an electric circuit. Magnetic Flux Definition: The number of magnetic lines of forces set up in a magnetic circuit is called Magnetic Flux. In this case, the magnetic stress on the Voltage Current and Flux Relations. a bigger inductor produces more flux per amp. Indications perpendicular to the magnetic flux will be stronger and more well defined than indications at an angle. The flux of a given quantity through a given surface area is a measure of how much of that quantity passes through the area. Magnetic Field Intensity Unit Magnetic field intensity is also known as the magnetizing force which is measured is ampere-turns per meter (A-t/m). MFL utilizes a powerful magnet that magnetizes the pipeline and then uses a flux sensor device that locates the points where there is leakage of magnetic field. It is denoted by φ m. The total magnetic flux through a closed surface is zero, according to Gauss's law for magnetism. M. ’ Magnetic flux is the number of magnetic field lines that pass through a surface. If we place an imaginary isolated unit north pole in a magnetic field it will experience a repulsive force from north pole and an attractive force from south pole of the magnet which has created the field. the lines of force surrounding a permanent magnet or a moving charged particle. The phenomenon of flux quantization was discovered by B. e. Magnetic flux density is equal to magnetic field strength times the magnetic permeability in the region in which the field exists. Magnetic flux is the flux density x area. com is a free service Sinhala Meaning of Magnetic flux from English. The shape of this magnetic field is more intense in some parts than others with the area of the magnet that has the greatest magnetism being called “poles”. Let us consider an open surface as shown below For an open surface, the area vector could be in any direction ( I've chosen an arbitrary direction which in this case is towards east ). It is the normal component of magnetic field which passes through the area. Apr 28, 2018 · Flux and flux density. Flux density (Magnetic flux density) B. Learn more. 3 Answers. Its SI unit is Weber (Wb) and its CGS unit is Maxwell. The magnetic flux measures through flux meter. I am a bit confused about the difference between flux cutting and flux linking when talking about magnetic fields and induced EMF. The flux linkage of the wire is the flux going through the closed surface created by the boundary of the wire. This fact is useful for simplifying magnetic field problems. Jan 31, 2017 · Flux linkage is defined by the following equation: Magnetic flux: Magnetic flux is defined as the rate of a magnetic field flowing through a given conductor’s cross-sectional area. The magnetic flux through a closed surface (such as a ball) is always zero. The magnetic flux is the measure of the strength of a magnetic field. net dictionary. where v is the velocity of the charge, which is moving at an angle θ to the direction of the field. In those undergoing exercise, metabolic fluxes and recovery rates were followed. The density of the lines indicates the magnitude of the magnetic field. The magnetic flux, symbol: Φ, is the surface integral of B , i. Search. Three examples of flux lines are shown in Nov 27, 2011 · So what does it mean by change of magnetic flux? How can I calculate the change in magnetic flux? This is how you calculate the magnetic flux = Tesla(Magnetic feild) X Surface area (cm^2) So by that formula, I have the magnetic flux, but how can I calculate the change in magnetic flux? and change in time? magnetic flux density: 1 n the amount of magnetic flux in a unit area perpendicular to the direction of magnetic flow Synonyms: magnetic field strength , magnetic induction , magnetic intensity Type of: field intensity , field strength the vector sum of all the forces exerted by an electrical or magnetic field (on a unit mass or unit charge or The appropriate combination of geometry and magnetic field needed to describe the induced electric field, when either changes, is called magnetic flux. The curves with the symbols filled in grey refer to the heat fluxes and are related to the right axis. flux: The rate of transfer of energy (or another physical quantity) through a given surface, specifically electric flux or magnetic flux. Fairbank [2] and, independently, by R. In simple words, Magnetic field x area perpendicular to the magnetic field (B) is called Magnetic Flux which is denoted by Φ or Φ m or Φ B. Magnetic field strength is one of two ways that the intensity of a magnetic field can be expressed. What does magnetic flux mean? Information and translations of magnetic flux in the most comprehensive dictionary definitions resource on the web. Electromagnetic induction was discovered by Michael Faraday in the 1830s. Translate From English into Sinhala. Magnetic permeability is a similar concept to this, but for magnetic flux instead of electricity. Magnetic flux density created by the surface current flowing over the toroidal current surface has only an azimuthal component and is concentrated inside the toroidal volume, in other words, there is no field of scattering in the idealized model. How to say magnetic flux Search magnetic flux and thousands of other words in English definition and synonym dictionary from Reverso. Units of B is Mini Physics Nov 17, 2006 · At the Sun's edge, in a region called the heliosphere, magnetic fields and electrical currents align and twist themselves in massive three-dimensional structures called "magnetic flux ropes. It gives the measurement of the total magnetic field that passes through a given surface area. 1 Tesla = 10 000 Gauss. magnetic flux density - the amount of magnetic flux in a unit area perpendicular to the direction of magnetic flow magnetic field strength , magnetic intensity , magnetic induction field intensity , field strength - the vector sum of all the forces exerted by an electrical or magnetic field (on a unit mass or unit charge or unit magnetic pole) at a given point in the field Magnetic flux is the number of lines of force linked with certain material. The rate of flow of magnetic energy across or through a surface Magnetic flux is the product of the average magnetic field times the perpendicular area that it crosses. Magnetic fields can usually be seen by magnetic flux lines. The magnetic flux density is the amount of flux per unit area. It is a way of describing the electric field strength at any distance from the charge causing the field. Conservation of magnetic flux gives1 φ = B0lx0 = φ(x) = Blx. The magnetic flux density at a point refers to the number of lines of force crossing unit area perpendicular to the field lines at the point, and this just translates to the magnetic field strength at that point. ‘The magnetic flux is measured by external coils, from which the conductivity inside the object can be calculated. At each end of a magnet is a pole. At the poles of a magnet, for example, where the magnetic field is strong, the field lines are crowded together,… Read More Magnetic Flux In general, Flux is the measurement of a quantity that flows through a surface in a given amount of time. So flux (Webers) = flux density X area Also the strength of a magnetic field can be measured by the force it exerts on a metre of conductor carrying a current of 1 Amp placed at right angles to the field. Introduction and intuition for flux and magnetic flux. In electromagnetism, electric flux is the measure of the electric field through a given surface, although an electric field in itself cannot flow. Definition of magnetic flux in the Legal Dictionary - by Free online English dictionary and encyclopedia. • MAGNETIC FLUX (noun) The noun MAGNETIC FLUX has 2 senses: 1. MFL is often used for integrity assessment of pipelines and storage tanks, but the principle can be applied to assets in any industrial sector. Magnetic flux field is generated by a permanent magnet within or on the surface of a permanent magnet motor. The magnetic flux created by the field windings follows the path of least magnetic reluctance. magnetic field, flux. Using this technique, any damage relating to topside or bottom side corrosion can be easily detected. A measure of the strength of a magnetic field in a given area. The SI unit of magnetic flux is the weber (Wb) (in derived units: volt ⋅ seconds), and the CGS unit is the maxwell. Magnetic flux is denoted by Φ B where B represents magnetic field, and its unit is measured in Weber (Wb). What does magnetic flux density mean? Information and translations of magnetic flux density in the most comprehensive dictionary definitions resource on the web. flux linkage is flux density x cross sectional area x number of turns in coil Field strength is technically different from flux density, but I don't think they care too much at a-level. Examples of “flux”. Meaning of magnetic flux. The strength of a magnet has to do with the spaces between the magnetic flux lines. The unit was announced during the General Conference on Weights and Measures in 1960 and is named [1] in honour of Nikola Tesla , upon the proposal of the Magnetic Flux Leakage is a magnetic approach for non-destructive testing which is used to detect corrosion in steel components such as pipelines and storage tanks. the amount of magnetic force that passes through a point in a magnetic field See magnetic flux in the Oxford Advanced American Dictionary Check pronunciation: magnetic flux Magnetic flux is the number of magnetic lines that passes through a surface (such as a loop of wire). What is a Magnetic Field A magnetic field is a region in space where magnetic poles and moving charges experience a force (assuming no electric field is present because they can also exert forces on charges). Skip navigation Sign in. How to pronounce, definition audio dictionary. This is where the magnetic field strength is the greatest. Aug 15, 2011 · Magnetic Flux vs Magnetic Flux Density . field of force, force field, field - the space around a radiating body within which its electromagnetic oscillations can exert force on another similar body not in contact with it. Magnetic flux. The magnetic flux through a closed surface is always zero which implies that there cannot be magnetic charges in classical electromagnetism. Feb 24, 2019 · magnetic flux. What is magnetic flux? Meaning of magnetic flux as a legal term. A magnet is said to have a north and a south pole; two magnets will repel each other when like poles face each other and attract each other when opposite poles come close to each other. Dictionary entry details. Describe methods to produce an electromotive force (emf) with a magnetic field or magnet and a loop of wire. Flux per unit of cross-sectional area is called flux density. Magnetic flux = Magnetic field * Area * (angle between the planar area and the magnetic flux) …continuous lines of force or magnetic flux that emerge from north-seeking magnetic poles and enter south-seeking magnetic poles. However the amount of magnetic flux flowing through a given area will change from one point to another around the magnet and you can understand this by thinking about a loop of wire placed in the field at two different points (A and B). Magnetic Flux Compression Generators: a Tutorial and Survey B0. These lines of flux are collectively referred to as the “magnetic field” of the magnet. Difference Between Magnetic Field & Magnetic Flux The most significant difference between the magnetic field and the magnetic flux is that the magnetic field is the region around the magnet where the moving charge experiences a force, whereas the magnetic flux shows the quantity or strength of magnetic lines produced by the magnet. It is measured in teslas or gausses and represented by the symbol "B". After the strip is positioned, energize the magnetic field and apply magnetic particles (wet suspension or dry powder). Magnetic flux Meaning. magnetic flux density n a measure of the strength of a magnetic field at a given point, expressed by the force per unit length on a conductor carrying unit current at that point. . yourdictionary. Magnetic flux is a measure of quantity of magnetism. In other words, the magnetic field does not cross the surface S anywhere, i. Dec 12, 2019 · A true definition of magnetic flux is considered a fairly advanced concept in physics and is often broken down into a simpler explanations. The symbol we use for flux is the Greek letter capital phi, . Flux linkage is the magnetic flux running through, or "linked" to a coil, so the field strength times the coil area. Thus, it is proportional to the number of magnetic field lines which pass through a surface. Technically, a distinction is made between magnetic field strength H, measured in amperes per meter (A/m), and magnetic flux density B, measured in Newton-meters per ampere (Nm/A), also called tesla s (T). Pronunciation (US): 1. It is the measurement of amount of magnetic flux in a particular area. It is a quantity of convenience in the statement of Faraday's Law and in the discussion of objects like transformers and solenoids . Apr 26, 2016 · Magnetic flux is the scalar product of the magnetic flux density and the area vector. The SI unit of magnetic flux is the weber (Wb) (in derived units: volt-seconds), and the CGS unit is the maxwell. Many electrical components and types of equipment work based on the principle of electromagnetic induction. Magnetic flux definition, the total magnetic induction crossing a surface, equal to the integral of the component of magnetic induction perpendicular to the surface over the surface: usually measured in webers or maxwells. We use cookies to enhance your experience on our website, including to provide targeted advertising and track usage. A magnetic field is represented by imaginary lines of force that we call magnetic flux. Assume the frequency of the voltage and the size of the winding to be low enough so that capacitance effects are negligible. magnetic flux according to the free Engineering Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. And, that's the flux of the magnetic field. To help improve the understanding of why the flux in a transformer roughly stays constant under load consider these four pictures and look at each one in turn: - Regards the infinite inductance part of the question, inductance is defined as total flux produced per amp i. The equation for magnetic flux is:, (Equation 20. Magnetic Flux. Faraday’s Law of Induction Faraday’s law of induction is a basic law of electromagnetism that predicts how a magnetic field will interact with an electric circuit to produce an electromotive force (EMF). Jun 10, 2016 · Magnetic flux depends on the shape of the surface and on the enclosed current. Magnetic flux is the amount of magnetic field passing through a unit area of a given surface. What does magnetic flux mean in law? Definition of magnetic flux in the Definitions. This article tries to give clear explanations for magnetic flux and magnetic flux density. . So this would have one magnetic flux. The closer the flux lines are to each other, the stronger the magnet is. One more point – the “tube” we are considering is a region we define, not a physical tube. 00 / 0 votes) Rate these synonyms: Magnetic flux, is a measure of quantity of magnetism, taking account of the strength and the extent of a magnetic field. the amount of magnetic flux in a unit area perpendicular to the direction of magnetic flow Familiarity information: MAGNETIC FLUX DENSITY used as a noun is very rare. continuous change: 2. magnetic field. It is calculated by the formula = B(Acos θ). (1) In the examples treated in this section, such as the one discussedhere,edge effectsare usually ignored and the magnetic field B is parallel to the flux-compressing conductor. The tesla (symbol: T) is a derived unit of the magnetic induction (also, magnetic flux density) in the International System of Units. If the field lines run in a straight line (e. Video transcript. Where the flux density(B) is the strength of the magnetic field at point. One tesla is equal to one weber per square metre . Magnetic flux and magnetic flux density are two phenomena encountered in electromagnetic field theory. The CGS unit is the Maxwell. And once again, it's based on, it's based on the strength of the magnetic field and specially the component of the magnetic field vectors that are perpendicular, that are perpendicular to this actual surface. Magnetic flux definition is - a measure of magnetic induction represented by lines of force. Deaver and W. It also describes different types of flux such as magnetic flux, electric flux, luminous flux, radiant flux, heat flux, mass flux, momentum flux, and acoustic flux. 1: Magnetic flux) where is the angle between the magnetic field and the area vector . You can see the remanence of our super magnets in this table. Figure 5-1 is a schematic diagram of an air-core reactor. The flux per unit area is proportional to the strength of the magnet. Assume that the flux density of the magnetic field is B and a circular coil having N turns is placed normal to the magnetic field. Sample measuring times are typically of the order of approximate hours with the currently available fluxes at neutron sources. A magnetic field at any given point can be seen as a vector in the direction of the field with a magnitude equal to the Lorentz force exerted on an electric wire oriented perpendicular to the lines of force, Oct 07, 2015 · Magnetic flux is a measurement of how much magnetic field passes through an area. , (Symbol) B (Also called) magnetic induction …magnetizing field divided by the magnetic field strength H of the magnetizing field. , (Symbol) B (Also called) magnetic induction Definition of magnetic-flux noun in Oxford Advanced American Dictionary. " As Synonyms for magnetic flux This thesaurus page is about all possible synonyms, equivalent, same meaning and similar words for the term magnetic flux . Magnetic flux (symbol, the Greek letter phi) is measured in webers (pronounced 'vay-bers'); the intensity of Oct 07, 2015 · Introduction and intuition for flux and magnetic flux. magnetic flux definition: the component of a magnetic field perpendicular to an area multiplied by the size of that area; a measure of the number of magnetic field lines passing through the area: it is measured in maxwells or webers: symbol, ? Jul 26, 2018 · We define magnetic flux as the total number of magnetic lines of force in a magnetic field. While the total amount of the flux produced by a magnet is important, we are more interested in how dense or concentrated, the flux is per unit of cross-sectional area. This means that the net magnetic flux through such a closed surface is always zero and therefore all the magnetic field lines going into the closed surface are exactly balanced by field lines coming out. The magnetic flux Φ is the magnetic flux density which runs through an imagined area. g. Magnetic flux is expressed by the SI (International System) unit weber, which equals one volt-sec. Definition from Wiktionary, the free dictionary. This video is unavailable. A vector quantity measuring the strength and direction of the magnetic field around a magnet or an electric current. lankadictionary. magnetic flux unit: 1 n a measure of the strength of a magnetic field per unit area Synonyms: flux unit Types: Mx , maxwell a cgs unit of magnetic flux equal to the flux perpendicular to an area of 1 square centimeter in a magnetic field of 1 gauss Wb , weber a unit of magnetic flux equal to 100,000,000 maxwells Type of: magnetic flux a Nov 17, 2011 · Difference Between Flux and Flux Linkage. Apr 26, 2015 · Video shows what magnetic flux means. The unit of measurement previously used was G (Gauss). Flux density is the measure of the number of magnetic lines of force per unit of cross-sectional area. Magnetic flux leakage (MFL) is a non-destructive testing method used to detect corrosion and pitting in steel pipelines. Jul 05, 2008 · Magnetic flux is in effect the 'amount' of magnetic field as measured by the field lines passing through the area. These phenomena are extremely important in fields such as physics, electronic engineering, telecommunication engineering, electrical engineering and particle physics. The higher the magnetic permeability the better the material allows for magnetic flux to pass Definition of Magnetic Flux \(\Phi\) This idea of calculating the amount of rain hitting a surface can be generalized by the concept of flux . Magnetic flux is defined as the total number of magnetic field lines through a given coil or area. Measuring flux is about drawing imaginary boundaries, not having a physical shape. Flux fringing is especially pertinent to magnetic cores with an air gap, for instance in flyback transformers or PFC inductors. Calculate the flux of a uniform magnetic field through a loop of arbitrary orientation. The term is also referred as magnetic Flux is the presence of a force field in a specified physical medium, or the flow of energy through a surface. The flux through an element of area perpendicular to the direction of magnetic field is given by the product of the magnetic field density and the area element. In a different way, flux is the measurement of a vector field that passes through a given area. Its unit is Weber. Magnetic Flux is defined as the number of magnetic field lines passing through a given closed surface. Jul 16, 2008 · The real definition of magnetic flux, which is valid for every surface and in every case, is: [tex]\Phi = \int_A B_n dA[/tex] which means that you have to sum (integral) the contributes of the perpendicular (normal) component of B in every point of the surface A. Magnetic flux density is usually represented in formulas with the symbol , a (pseudo) vector field. Of primary concern, however, is the magnetomotive force needed to establish a certain flux density, B in a unit length of the magnetic circuit. 2. The apparatus used by Faraday to demonstrate that magnetic fields can create currents is illustrated in Figure 1. I was originally under the impression that flux cutting was when there was relative motion between a conductor and a magnet and linking was when there was a change in the magnetic flux density. Electromagnetic induction is the production of voltage or electromotive force due to a change in the magnetic field. Magnetic flux density definition: a measure of the strength of a magnetic field at a given point, expressed by the force | Meaning, pronunciation, translations and examples magnetic flux A term referring to the lines of a magnetic field, which indicate the strength of a magnetic field. S. a substance added to a metal to make it easier to solder (= join by…. A magnetic circuit is made up of one or more closed loop paths containing a magnetic flux . plural magnetic fluxes) A measure of the strength of a magnetic field in a given area. ) (a) Obtaining a larger diameter coil while holding magnetic flux density n a measure of the strength of a magnetic field at a given point, expressed by the force per unit length on a conductor carrying unit current at that point. Flux is depicted as "lines" in a plane that contains or intersects electric charge poles or magnetic poles. a measure of the strength of a magnetic field over a given area. magnetic flux - the lines of force surrounding a permanent magnet or a moving charged particle. magnetic flux n a measure of the strength of a magnetic field over a given area perpendicular to it, equal to the product of the area and the magnetic flux density through it Symbol: φ T (Tesla) is used as the unit of measurement for magnetic induction and, respectively, magnetic flux density. Magnetic flux is given the symbol Φ and is measured in units called Webers (Wb). Flux is what is passing through the sides of a bucket at a moment in time. Follow Magnetic Flux to never miss another show. Its SI unit is weber (tesla/m^2) while CGS unit is maxwell. The area vector has a Related to magnetic flux: magnetic flux density, Magnetic field density flux, magnetic, in physics, term used to describe the total amount of magnetic field field, Magnetic flux is the product of the average magnetic field times the perpendicular area that it penetrates. Listen to The Definition of MAGNETIC FLUX by Magnetic Flux for free. Not only are the portals common, one space physicist contends they form twice as often as anyone had previously imagined. Magnetic flux density (B) is defined as the force acting per unit current per unit length on a wire placed at right angles to the magnetic field. Definition - What does Magnetic Flux mean? Magnetic Flux or Magnetic Flux Density is the amount of electromagnetic field that passes through a surface when it is brought near an electric current. In electronics, the term applies to any electrostatic field and any magnetic field . Based on the definition of the magnetic flux, which of the following will without a doubt increase the magnetic flux? (Select all that apply. (ie the density of lines of flux packed into a said area) Magnetic flux linkage is used when taking about magnetic flux in respect to a coil, where is shows the total magnetic flux is acting on n coils. English-Sinhala-English Multilingual Dictionary. The most basic definition is the magnetic flux through a plane figure due to a uniform magnetic field. Magnetic flux density B is a measure of the actual magnetic field within a material considered as a concentration of magnetic field lines, or flux,…. Magnetic flux refers in general to the lines of force in a magnetic field. Magnetic flux is a measure of the number of magnetic field lines passing through an area. Meaning of magnetic flux density. Explain why. com/magnetic-flux-density A vector quantity measuring the strength and direction of the magnetic field around a magnet or an electric current. www. I've never been able to really grasp the more advanced (and actually shorter) definition of magnetic flux but this article does a good job at defining it in a simple way. The magnetic core is designed so that a well defined gap is placed in the magnetic circuit for storing energy in magnetic field. induction of magnetism in a body when it is in a magnetic field or in the magnetic flux set up by a magnetomotive force —symbol B… See the full definition SINCE 1828 Definition of magnetic flux density in the Definitions. Or it is the amount of magnetic field or magnetic lines of force passing through a surface like conducting area, space, air, etc. Retrieved from https://www. At all times the direction of the magnetic field is shown by the direction of the magnetic flux lines. Doll and M. Magnetic permeability μ (Greek mu) is thus defined as μ = B / H. ’ ‘Alternatively, actively powered Hall effect sensors can measure the absolute magnetic flux. So, when we define the region of a “bucket”, it would not “fill up” with flux. Magnetic Flux Leakage (MFL) testing is a widely used, Non-Destructive Testing (NDT) method for the detection of corrosion and pitting in steel structures. Jan 02, 2019 · The page answers what is flux. Now, the magnetic flux associated with a surface is given by ∬→B⋅ˆndA The surface could be an open one or a closed one. The magnetic flux is most concentrated at the poles of a magnet. flux definition: 1. Nov 16, 2019 · The measure of the strength of a magnetic field is called magnetic flux density, or magnetic induction. Familiarity information: MAGNETIC FLUX used as a noun is rare. You can complete the definition of magnetic flux given by the English Definition dictionary with other English dictionaries: Wikipedia, Lexilogos, Oxford, Cambridge, Chambers Harrap, Wordreference, Collins Lexibase dictionaries, Merriam Webster In physics, specifically electromagnetism, the magnetic flux (often denoted Φ or Φ B) through a surface is the component of the B field passing through that surface. Nabauer, [3] in 1961. The SI Unit of magnetic flux is Wb (Weber). The SI unit of magnetic flux is the Weber (Wb) (in derived units: volt-seconds). Magnetic flux density is usually measured in teslas. This implies that there cannot be magnetic charges in classical electromagnetism. Definition of the Magnetic Flux Density A bipolar stepper motor contains a permanent magnet in the rotor and two windings with cores that form the stator electromagnets Magnetic flux density is a vector, which describes the characteristics of the force of the magnetic field, in particular its effect on the charged particles at a given point in The magnetic flux quantum Φ 0 is the quantum of magnetic flux passing through a superconductor. No indications will form if the strip is aligned parallel to (in line with) the magnetic flux. Loading Close. Princeton's WordNet (0. Magnetic Flux Density : Magnetic Flux Density is a force acting per unit current per unit length on a wire, which is placed at right angle to the magnetic field
