Current in a conductor consists of moving charges. The magnitude of the flux through rectangle is equal to the magnitudes of the flux through both the top and bottom faces. Your third finger will now be pointing in the direction of the force. OpenStax College, Back Emf. In the conductor, however, we find an electromotive force, to which in itself there is no corresponding energy, but which gives riseassuming equality of relative motion in the two cases discussedto electric currents of the same path and intensity as those produced by the electric forces in the former case. The input primary voltage Vp is also related to changing flux by: \[\mathrm { V } _ { \mathrm { p } } = - \mathrm { N } _ { \mathrm { [ } } \dfrac { \Delta \Phi } { \Delta \mathrm { t } }\]. Device for Exploring Eddy Currents and Magnetic Damping: A common physics demonstration device for exploring eddy currents and magnetic damping. Electric motors are found in applications as diverse as industrial fans, blowers and pumps, machine tools, household appliances, power tools, and disk drives. The magnetic flux passing through a surface of vector area A is, \[\Phi _ { \mathrm { B } } = \mathbf { B } \cdot \mathbf { A } = \mathrm { B } \mathrm { A } \cos \theta\]. The term "electric charge" refers to just two types of entities. The induced emf in a coil is equal to the rate of change of flux linkage. OpenStax College, Motional Emf. An electric generator rotates a coil in a magnetic field, inducing an EMF given as a function of time by =NABwsint. 2003-2022 Chegg Inc. All rights reserved. But when the small coil is moved in or out of the large coil (B), the magnetic flux through the large coil changes, inducing a current which is detected by the galvanometer (G). electric flux remains same. Today Change. Demonstration Equating the two forces, we get \(\mathrm{E=vB}\). For linear, non-dispersive, materials (such that B = H where , called the permeability, is frequency-independent), the energy density is: \[\mathrm { u } = \dfrac { \mathbf { B } \cdot \mathbf { B } } { 2 \mu } = \dfrac { \mu \mathbf { H } \cdot \mathbf { H } } { 2 }\]. (a) Electric flux, =110 3Nm 2/C Radius of the Gaussian surface, r=10.0cm Electric flux coming out through a surface depends on the net charge enclosed inside a body. This is one aspect of Lenzs lawinduction opposes any change in flux. Transformers cores use ferromagnetic materials with a permeability much higher than the air. electric displacement dielectric Gauss's law flux electric flux, property of an electric field that may be thought of as the number of electric lines of force (or electric field lines) that intersect a given area. E = d d t, \mathcal{E} = - \frac{d \Phi}{d t}, E = d t d ,. Since the rod is moving at v, the power P delivered by the external force would be: \[\mathrm { P } = \mathrm { F } _ { \mathrm { ext } } \mathrm { v } = ( \mathrm { iBL } ) \times \mathrm { v } = \mathrm { i } \varepsilon\]. Units of magnetic flux are T m 2. Why does a change in the magnetic flux induce an EMF? Second, the walls of the cylinder must be perpendicular to the plate. Flux is defined as Magnetic flux = ( M a g n e t i c f i e l d) ( A r e a) cos where is the angle between area and field vector. OpenStax College, Back Emf. September 17, 2013. Faradays 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). Current loop is stationary, and the magnet is moving. September 17, 2013. Free High School Science Texts Project, Electrodynamics: Generators and Motors. The EMF can be calculated from two different points of view: 1) in terms of the magnetic force on moving electrons in a magnetic field, and 2) in terms of the rate of change in magnetic flux. A motor becomes a generator when its shaft rotates. form of Ampere's Law. This is due to mutual inductance or Faraday's law of electromagnetic induction. Thus the magnetic flux enclosed by the rails, rod and resistor is increasing. It is a quantity that contributes towards analysing the situation better in electrostatic. said: That's still true, so this new version above is the Area of the loop changes Yes, this can also change the flux and inturn induce current. Some transformers even provide a variable output by allowing connection to be made at different points on the secondary coil. September 17, 2013. OpenStax College, Electric Generators. Select Gauss surface In this case a cylindrical pillbox 2. As it enters from the left, flux increases, and so an eddy current is set up (Faradays law) in the counterclockwise direction (Lenz law), as shown. conduction or "real" current (the physical Simple Transformer: A typical construction of a simple transformer has two coils wound on a ferromagnetic core that is laminated to minimize eddy currents. Question: a point charge produces an electric flux of +235Nm^2/C through a gaussian sphere of radius 15.0cm centered on the charge. how will change in electric flux produces magnetic field and change in magnetic flux produces electrical field??? c. increases as the magnetic field decrease. Inductance is of two types Self-inductance: This is the phenomena in which change in electric current produce an electromotive force in the . e. None of the above RIIR-I defines a relationship between: a, the . September 17, 2013. A change in the field produced by the top coil induces an EMF and, hence, a current in the bottom coil. Energy is needed to generate a magnetic field both to work against the electric field that a changing magnetic field creates and to change the magnetization of any material within the magnetic field. Transformers run backward with the same effectiveness, or mutual inductance M. Self-inductance, the effect of Faradays law of induction of a device on itself, also exists. When the coils are stationary, no current is induced. how will change in electric flux produces magnetic field and change in magnetic flux produces electrical field??? This estimate of the flux gets better as we decrease the size of the patches. Magnetic Flux. If a changing magnetic flux produces an electric field, If you were to place a moving charged particle in a magnetic field, it would experience a force called the Lorentz force: \[\mathrm { F } = \mathrm { q } \times \mathrm { v } \times \mathrm { B }\], Right-Hand Rule: Right-hand rule showing the direction of the Lorentz force. iconduction + o The electric flux will therefore also be time dependent, and the rate of change of electric flux is equal to (35.4) The magnetic field around the wire can now be found by modifying Ampere's law (35.5) . A step-up transformer is one that increases voltage, whereas a step-down transformer decreases voltage. Lenz' Law: (a) When this bar magnet is thrust into the coil, the strength of the magnetic field increases in the coil. In fact, if the induced EMF were in the same direction as the change in flux, there would be a positive feedback that would give us free energy from no apparent sourceconservation of energy would be violated. The EMF can be calculated from two different points of view: 1) in terms of the magnetic force on moving electrons in a magnetic field, and 2) in terms of the rate of change in magnetic flux. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Eddy currents can produce significant drag, called magnetic damping, on the motion involved. Maxwell's Equation includes a term called displacement current. The rate of change of the electric displacement field is known as the displacement current. A transformer is an electromagnetic machine used to transfer electric energy between two circuits through a varying magnetic flux. If, however, the bob is a slotted metal plate, as shown in (b), there is a much smaller effect due to the magnet. technician said: AC flowing in the coil will produce an AC magnetic flux which will produce an AC emf. Note that this is exactly the power dissipated in the loop (\(\mathrm{= current \times voltage}\)). Magnetic Flux It is a device that converts mechanical energy to electrical energy. Current is rate of change of electric flux (aka charge) only. The energy stored by an inductor is \(\mathrm { E } _ { \mathrm { stored } } = \frac { 1 } { 2 } \mathrm { L } \mathrm { I } ^ { 2 }\). As seen in Figure 4, B cos = B, which is the component of B perpendicular to the area A. The time rate of change in the magnetic field produces an induced emf b. Overview. We've expounded on the fact that an Emf A generator forces electric charge (usually carried by electrons) to flow through an external electrical circuit. the magnetic field changes. ) Is there a useful physical quantity related to how effective a given device is? Second, EMF is greatest when the change in time t is smallestthat is, EMF is inversely proportional to t. The flux through each of the individual patches can be constructed in this manner and then added to give us an estimate of the net flux through the entire surface S, which we denote simply as . = N i = 1i = N i = 1Ei Ai(Npatchestimate). Magnetic field stores energy. Here \(\mathrm{r=w/2}\), so that \(\mathrm{v=(w/2)}\), and: \[\varepsilon = 2 \mathrm { B } l \frac { \mathrm { w } } { 2 } \omega \sin \omega \mathrm { t } = ( \operatorname { lw } ) \mathrm { B } \omega \sin \omega \mathrm { t }\]. If the bob is metal, there is significant drag on the bob as it enters and leaves the field, quickly damping the motion. The energy stored by an inductor is equal to the amount of work required to establish the current through the inductor, and therefore the magnetic field. January 16, 2015. Since the input voltage is AC, a time-varying magnetic flux is sent to the secondary, inducing its AC output voltage. from Gauss theorem, electric flux through the gaussian surface is the ratio of charge enclosed inside the gaussian surface to the permittivity of medium. Due to the force, electrons will keep building up on one side (bottom end in the figure) until enough of an electric field opposing the motion of electrons is established across the rod, which is \(\mathrm{eE}\). September 17, 2013. C. Solving Induction Problems 1. The property of an electrical component that causes an emf to be generated by changing the current flow is known as inductance. A point charge produces an electric flux of + 235 N m 2 / C through a gaussian sphere of radius 15.0 c m centered on the charge. Therefore, this energy can be modeled as being stored in the magnetic field. OpenStax College, Eddy Currents and Magnetic Damping. Transformers transform voltages from one value to another; its function is governed by the transformer equation. From Eq. where \Phi is the magnetic flux through the loop (recall that emf points in the opposite direction as the voltage).In general, one determines \Phi as a function of t t t, which allows for the . Charges in the vertical wires experience forces parallel to the wire, causing currents. Motional EMF produced by a moving conductor in a uniform field is given as follows, To keep the rod moving at a constant speed v, we have to apply an external force F. Lenz' law guarantees that the motion of the rod is opposed, and therefore the law of energy conservation is not violated. Entering these quantities into the expression for EMF yields: \[\mathrm { EMF } = \dfrac { \mathrm { B } \Delta \mathrm { A } } { \Delta \mathrm { t } } = \mathrm { B } \dfrac { l \Delta \mathrm { x } } { \Delta \mathrm { t } } = \mathrm { B } \mathrm { lv } \], To find the direction of the induced field, the direction of the current, and the polarity of the induced EMF we apply Lenz law, as explained in Faradays Law of Induction: Lenz Law. Note that the area swept out by the rod is \(\mathrm{A=x}\). A change in the field produced by the top coil induces an EMF and, hence, a current in the bottom coil. Faraday's law of induction can be used to calculate the motional EMF when a change in magnetic flux is caused by a moving element in a system. Note the generator is similar to a motor, except the shaft is rotated to produce a current rather than the other way around. September 17, 2013. $#=" rr The electric current produces a magnetic field B= 0 ni, which changes with time, and produces an electric field.The magnetic flux through circular disks =BdA is related to the circulation of the electric field on the circumference Eds. September 17, 2013. (N is dropped from our previous expression. The time rate of change in the electric field produces an induced emf c. The time rate of change in the magnetic flux produces an induced current. Steam Turbine Generator: A modern steam turbine generator. Energy is needed to generate a magnetic field both to work against the electric field that a changing magnetic field creates and to change the magnetization of any material within the magnetic field. Eddy Currents Induced in a Slotted Metal Plate: Eddy currents induced in a slotted metal plate entering a magnetic field form small loops, and the forces on them tend to cancel, thereby making magnetic drag almost zero. Figure shows the magnetic field produced by a current in a circular coil. OpenStax College, The Hall Effect. For if the magnet is in motion and the conductor at rest, there arises in the neighbourhood of the magnet an electric field with a certain definite energy, producing a current at the places where parts of the conductor are situated. The magnetic field B is into the page, perpendicular to the moving rod and rails and, hence, to the area enclosed by them. Possible sources of mechanical energy include: a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hand crank, compressed air, or any other source of mechanical energy. First, EMF is directly proportional to the change in flux . January 16, 2015. The greater the rate of change of flux, the larger is the induced emf. Electric flux is proportional to the number of electric field lines going through a virtual surface. There is no discernible effect on a bob made of an insulator. It consists of two inductor coils separated by two equal parallel lines representing the core. But when the small coil is moved in or out of the large coil (B), the magnetic flux through the large coil changes, inducing a current which is detected by the galvanometer (G). A device that exhibits significant self-inductance is called an inductor, and the EMF induced in it by a change in current through it is EMF = L I/t. Faradays 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). A change in the current I1 in one device, coil 1, induces an EMF2 in the other. This is proportional to the number of field lines cutting the area element. February 7, 2013. The present project tasks are subjected to change and will be adapted depending on the interests and ski Number of positions 1 Academic Level Year 3 Location of project in-person MECH 013: Investigating the relationship between the mechanical properties of FFF filaments and their printability using AON 3D-printer Professor Pascal Hubert pascal . electric field flux. OpenStax College, Electric Generators. (b) There is little effect on the motion of a slotted metal bob, implying that eddy currents are made less effective. If eddy currents are to be avoided in conductors, then they can be slotted or constructed of thin layers of conducting material separated by insulating sheets. February 8, 2013. When the magnet moves away from the coil, a current is again induced but now in opposite direction. Silver Price Today UK in GBP per Ounce. Input EMF that powers a motor can be opposed by the motors self-generated EMF, called the back EMF of the motor. Motion in a magnetic field that is stationary relative to the Earth induces motional EMF (electromotive force). Generators illustrated in this Atom look very much like the motors illustrated previously. d/DTE. Note that these angles can also be given as 180 + 180 + . In a motor, a current-carrying coil in a magnetic field experiences a force on both sides of the coil, which creates a twisting force (called a torque) that makes it turn. But if the magnet is stationary and the conductor in motion, no electric field arises in the neighbourhood of the magnet. Explanation, How Electric Fields arise from changing so, if the radius of gaussian surface is doubled. The rails are stationary relative to B, and are connected to a stationary resistor R (the resistor could be anything from a light bulb to a voltmeter). Score: 4.3/5 (27 votes) . September 17, 2013. In this Atom, we will learn about an alternative mathematical expression of the law. magnetic flux: A measure of the strength of a magnetic field in a given area. The induced EMF produces a current that opposes the change in flux, because a change in flux means a change in energy. current? The magnetic field created by the primary is mostly confined to and increased by the core, which transmits it to the secondary coil. Most electric motors use the interaction of magnetic fields and current -carrying conductors to generate force. Steam Turbine Generator: A modern steam turbine generator. OpenStax College, Motional Emf. Induction is the process in which an emf is induced by changing magnetic flux. Conducting Plate Passing Between the Poles of a Magnet: A more detailed look at the conducting plate passing between the poles of a magnet. 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of induction in a form of equation, Identify process that induces motional electromotive force, Explain the relationship between the motional electromotive force, eddy currents, and magnetic damping, Describe the relationship between the changing magnetic field and an electric field, Explain how an electromotive force is induced in electric generators, Explain how force is generated into electric motors, Describe properties of an inductor, distinguishing mutual inductance and self-inductance, Formulate two views that are applied to calculate the electromotive force, Apply the law of conservation of energy to describe the production motional electromotive force with mechanical work, Express the energy density of a magnetic field in a form of equation, Apply the transformer equation to compare the secondary and primary voltages. OpenStax College, Electric Generators. The type of transformer considered here is based on Faradays law of induction, and is very similar in construction to the apparatus Faraday used to demonstrate that magnetic fields can create currents (illustrated in ). A device that exhibits significant self-inductance is called an inductor. . That is, when a motor is doing work and its shaft is turning, an EMF is generated. Self-inductance is the effect of the device inducing emf in itself. force. For linear, non-dispersive, materials (such that B = H where , called the permeability, is frequency-independent), the energy density is: Transformers are often used at several points in the power distribution systems and also in many household power adapters. electric field lines dt d Eds B C! We learned the relationship between induced electromotive force (EMF) and magnetic flux. Assuming, as we have, that resistance is negligible, the electrical power output of a transformer equals its input. September 17, 2013. Transformers, for example, are designed to be particularly effective at inducing a desired voltage and current with very little loss of energy to other forms (see our Atom on Transformers. created by: Dr. Scott Dwyer - 2002 Faraday's Apparatus: This is Faraday's apparatus for demonstrating that a magnetic field can produce a current. i.e., here it is clear that electric flux doesn't depend on shape and size of gaussian surface. The electric field E can exert a force on an electric charge at any point in space. So if Area changes - flux changes and thus emf has a non zero value. b. is maximum when the plane of the loop is perpendicular to the magnetic field. The current loop is moving into a stationary magnet. This expression is valid, but it does not give EMF as a function of time. a changing magnetic field (actually a changing magnetic The answer is that the source of the work is an electric field E E that is induced in the wires. The direction of the magnetic field is into the screen. So we have.. B Ds = o o d/DTE You remember our "old" Ampere's Law which said: B Ds = o i Mutual inductance is the effect of two devices in inducing emfs in each other. Electric Flux is defined as a number of electric field lines, passing per unit area. Energy density is the amount of energy stored in a given system or region of space per unit volume. Lenz law is a consequence. LINK TO ORIGINAL PROBLEM: http://i.imgur.com/e8Tmt.png shows what happens to the metal plate as it enters and leaves the magnetic field. Once the relationship between H and B is known this equation is used to determine the work needed to reach a given magnetic state. the magnetic field through a loop, or you change the area Right hand rule gives the current direction shown, and the polarity of the rod will drive such a current. It is another physical quantity to measure the strength of electric field and frame the basics of electrostatics. But what about when the loop is still and Third, the distance from the plate to the end caps d, must be the same above and below the plate. Generators supply almost all of the power for the electric power grids which provide most of the worlds electric power. Their mutual inductance M indicates the effectiveness of the coupling between them. Modified In fact, the equivalence of the two phenomena is what triggered Albert Einstein to examine special relativity. Since the flux is increasing, the induced field is in the opposite direction, or out of the page. OpenStax College, College Physics. Taking the ratio of these last two equations yields a useful relationship: \[\dfrac { \mathrm { V } _ { \mathrm { s } } } { \mathrm { V } _ { \mathrm { p } } } = \dfrac { \mathrm { N } _ { \mathrm { s } } } { \mathrm { N } _ { \mathrm { p } } }\]. No current flows through the galvanometer when the switch remains closed or open. As discussed in Motional EMF, motional EMF is induced when a conductor moves in a magnetic field or when a magnetic field moves relative to a conductor. Transformer Setup: Transformers change voltages at several points in a power distribution system. Equate = qencl/ 0 2EA = qencl/ 0 4. Conversely, if voltage decreases, current increases. To find the magnitude of EMF induced along the moving rod, we use Faradays law of induction without the sign: \[\mathrm { EMF } = \mathrm { N } \frac { \Delta \Phi } { \Delta \mathrm { t } } \]. (b) Lenz's law gives the directions of the induced field and current, and the polarity of the induced emf. Their mutual inductance M indicates the effectiveness of the coupling between them. If a changing magnetic flux produces an electric field, then if the universe is a nice place, by symmetry it should follow that a changing electric flux produces a magnetic field. Device for Exploring Eddy Currents and Magnetic Damping: A common physics demonstration device for exploring eddy currents and magnetic damping. Generators supply almost all of the power for the electric power grids which provide most of the worlds electric power. were asked how an Emf can be generated if a loop is The other charged objects or particles in this space also experience some force exerted by this field, the intensity and type of force exerted will be dependent on the charge a particle carries. 2 we can confirm that motional and induced EMF yield the same result. Lenz law tells us the induced EMF opposes any change, so that the input EMF that powers the motor will be opposed by the motors self-generated EMF, called the back EMF of the motor. a magnetic field. cause electrons or charge carriers to move and create If not a magnetic force, then it must be an electric Since the rate of change of the magnetic flux passing through the loop is \(\mathrm{B\frac{dA}{dt}}\)(A: area of the loop that magnetic field pass through), the induced EMF \(\mathrm{_{induced}=BLv}\) (Eq. Assuming, as we have, that resistance is negligible, the electrical power output of a transformer equals its input. a. requires time varying magnetic field. September 17, 2013. Equivalence of the two phenomena is what triggered Einstein to work on special relativity. Motional and induced EMF are the same phenomenon, just observed in different reference frames. This classic unification of electric and magnetic forces into what is called the electromagnetic force is the inspiration for contemporary efforts to unify other basic forces. (b) Induced EMF. Equipment * The magnetic flux is \(\Phi _ { \mathrm { B } } = \int _ { \mathrm { S } } \vec { \mathrm { B } } \cdot \mathrm { d } \vec { \mathrm { A } }\) where \(\mathrm{\vec { A }} \) is a vector area over a closed surface S. A device that can maintain a potential difference, despite the flow of current is a source of electromotive force. where M is the same as for the reverse process. (b) Lenzs law gives the directions of the induced field and current, and the polarity of the induced emf. The induced EMF produces a current that opposes the change in flux, because a change in flux means a change in energy. Electric generators convert mechanical energy to electrical energy; they induce an EMF by rotating a coil in a magnetic field. E ds = o d/dt B. tangent to a circular path. As the change begins, the law says induction opposes and, thus, slows the change. The direction (given by the minus sign) of the EMF is so important that it is called Lenz law after the Russian Heinrich Lenz (18041865), who, like Faraday and Henry, independently investigated aspects of induction. large taka loan app customer care number//7865998681//large taka loan app customer care Large Taka Loan CUSTOMER Care NuMbeR 7978176592//Call Me. This is reduced to 120, 240, or 480 V for safety at the individual user site. Also, note that in the right hand side \(\frac { \partial } { \partial \mathrm { t } } \left( \int \vec { \mathrm { B } } \cdot \mathrm { d } \vec { \mathrm { A } } \right) = \int \frac { \partial \vec { \mathrm { B } } } { \partial \mathrm { t } } \cdot \mathrm { d } \vec { \mathrm { A } }\). The two coils are called the primary and secondary coils. Find the electric flux through the square, when the normal to it makes the following angles with electric field: (a) 30 30 , (b) 90 90 , and (c) 0 0 . Any change in magnetic flux induces an electromotive force (EMF) opposing that changea process known as induction. What is . (B, l, and v are all perpendicular to each other as shown in the image below. Concepts* Faraday found that the induced emf E \mathcal{E} E (electromotive force) through a current loop was given by. Transformers are also used at several points in power distribution systems, as shown in. In this unit of The Physics Classroom, we will explore the reasons for why charge flows through wires of electric circuits and the variables that affect the rate at which it flows. Faraday's law of induction is one of the four equations in Maxwell's equations, governing all electromagnetic phenomena. Note the generator is similar to a motor, except the shaft is rotated to produce a current rather than the other way around. d. The time rate of change in the magnetic flux produces an induced emf. Here, the net flux through the cube is equal to zero. a) What is the flux through a gaussian sphere with a radius 27.5cm? Therefore, a current-carrying coil in a magnetic field will also feel the Lorentz force. If there is no change, there is no induction. Faradays 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. In this Atom, we concentrate on motion in a magnetic field that is stationary relative to the Earth, producing what is loosely called motional EMF. The minus in the Faraday's law means that the EMF creates a current I and magnetic field B that oppose the change in flux this is known as Lenz' law. The minus in the Faradays law means that the EMF creates a current I and magnetic field B that oppose the change in flux this is known as Lenz law. (Note that "E2 induced" represents the induced emf in coil 2. (b) and (c) are two other situations. It does not depend on the size of the body. September 17, 2013. Expert Answer A changing electric flux does not produce magnetic flux because according to Maxwell's equations, the total magnetic fluc through a closed loop is zero.Hence, no emf can be induced.This can also be attributed to the fact that if there is a closed loop then only one magnetic pole will exist, which can never happen. Now \(\mathrm{=(BA)=BA}\), since B is uniform. OpenStax College, Faradayu2019s Law of Induction: Lenzu2019s Law. OpenStax College, College Physics. 8/12/03. When the switch is opened and closed, the galvanometer registers currents in opposite directions. When flux changes, an EMF is induced according to Faradays law of induction. OpenStax College, Motional EMF. As seen in Fig 1 (b), F lux is increasing, since the area enclosed is increasing. OpenStax College, College Physics. so the electric force on a charge carrier is always Electric Field: electric field is a field or space around a stable or moving charge in the form of a charged particle or between the two voltages. The current induced in the coil creates another field, in the opposite direction of the bar magnet's to oppose the increase. Most devices have a fixed geometry, and so the change in flux is due entirely to the change in current I through the device. The set of coil on left side of the core is marked as the primary and there number is given as N p. The voltage across the primary is given by V p. The set of coil on right side of the core is marked as the secondary and there number is represented as N s. The voltage across the secondary is given by V s. A symbol of the transformer is also shown below the diagram. That's why charge carriers In a motor, a current-carrying coil in a magnetic field experiences a force on both sides of the coil, which creates a twisting force (called a torque) that makes it turn. In a nutshell, the law states that changing magnetic field(\(\frac { d \Phi _ { \mathrm{B} } } {\mathrm{ d t} }\)) produces an electric field (\(\)), Faradays law of induction is expressed as \(\varepsilon = - \frac { \partial \Phi _ { \mathrm { B } } } { \partial \mathrm { t } }\), where \(\) is induced EMF and \(\frac { d \Phi _ { \mathrm{B} } } {\mathrm{ d t} }\) is magnetic flux. 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