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This paper provides a comprehensive overview of electromagnetic induction, primarily focused on Faraday's Laws. It explains the basic principles governing the induction process, including the relationship between changing magnetic flux and induced electromotive force (emf). The paper discusses methods for producing induced emf, the concept of self-inductance, and practical applications of eddy currents.
American Journal of Physics, 2004
We describe an experiment in which the induced electromotive force in a coil caused by an accelerating magnet and the position of the moving magnet are measured as a function of the time. When the circuit is completed by adding an appropriate load resistor, a current that opposes the flux change is generated in the coil. This current causes a magnetic field in the coil which decreases the acceleration of the rising magnet, as is evident from the position versus time data. The circuit provides a direct observation of effects that are a consequence of Lenz's law. The energy dissipated by the resistance in the circuit is shown to equal the loss in mechanical energy of the system to within experimental error, thus demonstrating conservation of energy. Students in introductory physics courses have performed this experiment successfully.
viXra, 2017
In this paper, Faraday’s law of induction was further investigated. The purpose is to see that besides there is the change of magnetic flux through the region enclosed by a conductor loop, if the magnetic flus change inside the wire of the loop is also required to generate an induction current in the conductor loop. An experiment is design and performed. The result shows that it is also a necessary condition that there is magnetic flux change inside the wire of the loop to generate an induction current in the conductor loop.
Physics, 2020
Faraday's Law of induction is often stated as "a change in magnetic flux causes an EMF"; or, more cautiously, "a change in magnetic flux is associated with an EMF"; It is as well that the more cautious form exists, because the first "causes" form is incompatible with the usual expression $V = - \partial_t \Phi$. This is not, however, to deny the causality as reasonably inferred from experimental observation - it is the equation for Faraday's Law of induction which does not represent the claimed cause-and-effect relationship. Here I investigate a selection of different approaches, trying to see how an explicitly causal mathematical equation, which attempts to encapsulate the "a change in magnetic flux causes ..." idea, might arise.
EPL (Europhysics Letters), 2008
The definition of the induced emf as the integral over a closed loop of the Lorentz force acting on a unit positive charge leads immediately to a general law for electromagnetic induction phenomena. The general law is applied to three significant cases: moving bar, Faraday's and Corbino's disc. This last application illustrates the contribution of the drift velocity of the charges to the induced emf : the magneto-resistance effect is obtained without using microscopic models of electrical conduction. Maxwell wrote down 'general equations of electromotive intensity' that, integrated over a closed loop, yield the general law for electromagnetic induction, if the velocity appearing in them is correctly interpreted. The flux of the magnetic field through an arbitrary surface that have the circuit as contour is not the cause of the induced emf. The flux rule must be considered as a calculation shortcut for predicting the value of the induced emf when the circuit is filiform. Finally, the general law of electromagnetic induction yields the induced emf in both reference frames of a system composed by a magnet and a circuit in relative uniform motion, as required by special relativity. pacs 03.50.De First pacs description
This essay studies the relation among current, turns of coil and electromagnetic field in order to investigate what causes to electromagnetic field production in cell phone chargers. The research is conducted with a closed circuit including a rheostat and a coil. Change of the electromagnetic field's magnitude has been observed by changing the total current in the circuit and the turns of coil. The current was systematically increased in order to observe the change in electromagnetic field. The change is observed with each magnitude of current for different turns of coils to prove the expected uniform increase in electromagnetic field. The results were recorded by electromagnetic field sensor probe and current probe. Comparison of the results of experiments was used to find the relation of current and electromagnetic field. The result of each experiment was compared with the mathematical concept of Ampere's Law to prove suggested mathematical formula. The research showed that there is a relation among current, turns of coil and the electromagnetic field. Uniform increase in electromagnetic field has been observed when the current and number of turns of coil is systematically increased. Considering that the cell phone chargers are carrying coils, it could be stated that they produce electromagnetic field directly proportional to current. Also, the electromagnetic field that is produced by the charger is directly proportional to the turns of coil that it includes.
2014
Different variants of electromagnetic induction are considered. The type of induction caused by changes of electromagnetic induction flow is separated. The dependence of this induction on the flow density of electromagnetic energy emf and on the parameters of the wire is explored. We are discussing the mechanism of occurrence of energy flow, which enters the wire and compensates the heat loss.
2012
Profile of induced eletromotive force (EMF) for a circular loop (CL) entering and leaving a limited rectangular area which has perpendicular uniform magnetic field is reported in this work. The influence of parameters of the sytem to the induced EMF profile is discussed.
Experimental validation of the Faraday’s law of electromagnetic induction (EMI) is performed when an electromotive force is generated in thin copper turns, located inside a large magnetic coil. It has been established that the electromotive force (emf) value should be dependent not only on changes of the magnetic induction flux through a turn and on symmetry of its crossing by magnetic power lines also. The law of EMI is applicable in sufficient approximation in case of the changes of the magnetic field near the turn are symmetrical. Experimental study of the induced emf in arcs and a direct section of the conductor placed into the variable field has been carried out. Linear dependence of the induced emf on the length of the arc has been ascertained in case of the magnetic field distribution symmetry about it. Influence of the magnetic field symmetry on the induced emf in the arc has been observed. The curve of the induced emf in the direct section over period of current pulse is similar to this one for the turns and arcs. The general law of EMI for a curvilinear conductor has been deduced. Calculation of the induced emf in the turns wrapped over it and comparison with the experimental data has been made. The proportionality factor has been ascertained for the law. Special conditions have been described, when the induced emf may not exist in the presence of inductive current. Theoretical estimation of the inductive current has been made at a induced low voltage in the turn. It has been noted the necessity to take into account the concentration of current carriers in calculation of the induced emf in semiconductors and ionized conductors
2020
The objectives of the experiment are to determine the magnetic field along the horizontal x-axis that passes through the centre of a single solenoid coil, and to determine the magnetic field along the horizontal x-axis that passes through the centre of the Helmholtz coil. Helmholtz coil is a device that produces a region of a nearly uniform magnetic field. It consists of two solenoids that are parallel to each other on the same axis. Both solenoids are separated by a distance, d. Each coil carries an equal electric current in the same direction. The entire experiment is conducted via a simulator software provided. For Experiment I, the graph of B vs x is obtained alongside with the logarithmic graph of B vs the square of x. The comparison of the experimental and the theoretical logarithmic graphs allows the determination of the turns of wire, N of the hypothetical single coil. That is, N = 1717.5. It is managed to obtain the best value for B_0 through the standard deviation as the uncertainty in a single measurement with 70% confidence. That is, B_0 = (4.1267 x 10-3) ± (9.2236 x 10-5) T. The experimental μ_0 is deduced and it is given by μ_0 = (2.5292 x 10-7) T m A^-1. The determination of the experimental μ0 yields a percentage error of 79.9%. For Experiment II, the graph of B vs x is obtained for all d = R, d = 1.5R and d = 0.5R. Two major things found out in this part are, firstly, the mathematical erratum in either the simulator or in the laboratory manual is very substantial, and secondly, the erratum has caused such an ambiguity that a thorough quantitative analysis has become cumbersome given the time constraint as the deviation between the experimental and the theoretical values are of logarithmic. Next, the graph of B_0 vs d is also obtained for both the experimental and the theoretical values. Nothing much could be done on the quantitative aspect of it. However, qualitatively, it is observed that as d increases, B decreases. This may explain the lesser incident flux density as the coils move further apart. Lastly, the slope of the experimental data has a greater rate of change as opposed to that of the theoretical values.
IJEER , 2022
Cycling of Induced Magnets (CIM) within the interruption of repulsion is a new discovered phenomenon that utilizes the inherent induction and repulsion properties of magnetic materials. The cyclic motion of magnetic conductors, the effect of CIM, is utilized to facilitate the prime mover action for generation of electrical energy as per Faraday’s law. This CIM may leads to the innovation and development of new technology in the area of electrical power generation. In this paper the foundation stage, which can be referred as ‘Zero Base’ stage of the new discovered principle of CIM, is stated and detailed cause effect and orientation prospects for the justification of the principle is discussed. The application of the outcome of CIM for electrical power generation possibility is also presented
URSI Radio Science Bulletin, 2017
Magnetic Sensors - Principles and Applications, 2012
Progress In Electromagnetics Research B, 2011
Measurement Techniques, 1970
Fourth Electromagnetic Induction. The Papers of Independent Authors, ISSN 2225-6717, 2022, 55(1), 19–26., 2022
Variants of electromagnetic induction are considered. It is shown that there is also an induction caused by the existence of a flow of electromagnetic energy. The dependence of emf is found. this induction on the electromagnetic energy flux density.
Physics Education, 2010
We investigate the electromagnetic induction phenomenon for a falling, oscillating and swinging magnet and a coil, with the help of a datalogger. For each situation, we discuss the salient aspects of the phenomenon, with the aid of diagrams, and relate the motion of the magnet to its mathematical and graphical representations. Using various representation modes to guide student thinking on how the variation of the magnetic flux can be used to predict the induced electromotive force should help students develop a deeper and more coherent conceptual understanding of the phenomenon.
This experiment is conducting two tests in which are the ferromagnetic hysteresis and the magnetic induction. The ferromagnetic hysteresis will study the hysteresis loop characteristic for different iron core. While the magnetic induction test will study on the factors that affect the magnetic induction.