LITTLE STINKERS: Electromotive Force and Faraday's Law of Electromagnetic Induction

1963 ◽  
Vol 1 (3) ◽  
pp. 133-134 ◽  
Keyword(s):  
Electromotive Force ◽  
Electromagnetic Induction ◽  
Faraday’S Law

Modelling electromagnetic induction via accelerated electron motion

2015 ◽  
Vol 93 (7) ◽  
pp. 802-806 ◽  
Author(s):  
Ray T. Smith ◽  
Stephen Taylor ◽  
Simon Maher
Keyword(s):  
Electromotive Force ◽  
Electromagnetic Induction ◽  
Close Agreement ◽  
Scientific Literature ◽  
Causal Explanation ◽  
Analytical Calculation ◽  
Low Frequency ◽  
Alternating Current ◽  
Principle Of Superposition ◽  
Faraday’S Law

The two forms of electromagnetic induction are generally referred to as motional and transformer induction, and although these phenomena have been observed and discussed for well over 150 years, certain aspects remain controversial in the scientific literature. It is well-known that an electromotive force (emf) is induced in a loop of wire encircling a long solenoid carrying alternating current. This is true however even in a region in which there is a negligibly small magnetic or electric field. Although the flux linking concept can explain the induced emf, more recent explanations utilise the concept of vector potential as the causal explanation of induction. In this present investigation, we propose that Weber’s force, based on inter-particle forces, provides a more fundamental explanation. The induced emf is measured directly across a closely wound, 1000 turn narrow coil encircling a long solenoid carrying alternating current. Weber’s force formula has been adapted to the case of transformer induction by treating the solenoid as a stack of current loops and applying the principle of superposition. Analytical calculation is also included for the application of Faraday’s law. Close agreement with experimentally measured values is demonstrated in all cases for low-frequency induction up to around 5 kHz.

Rethinking Faraday's law for teaching motional electromotive force

2012 ◽  
Vol 33 (2) ◽  
pp. 397-406 ◽  
Author(s):  
Kristina Zuza ◽  
Jenaro Guisasola ◽  
Marisa Michelini ◽  
Lorenzo Santi
Keyword(s):  
Electromotive Force ◽  
Faraday’S Law

Electromagnetism

2012 ◽  
Author(s):  
Charles M. Epstein
Keyword(s):  
Energy Flow ◽  
Electromotive Force ◽  
Electromagnetic Induction ◽  
Magnetic Stimulation ◽  
Eddy Currents ◽  
Flow System ◽  
Human Beings ◽  
Induced Voltage ◽  
Secondary Currents ◽  
Primary Current

This article elucidates on the concept of electromagnetism and electromagnetic induction with a view to explaining the theory of magnetic stimulation, used to cure diseases in human beings. Magnetic stimulation follows the principles of electromagnetism. A changing primary current induces secondary currents, which are called eddy currents, in the nearby conductors (human tissue in this case). The strength of the electric field is measured by its electromotive force (emf), which in turn, is measured in volts. The changing primary current also gives rise to an induced voltage in the primary loop itself. The essential circuitry of a magnetic stimulator is composed of three elements, the capacitor, inductance of the stimulation coil, and a switch to connect them. This article also explains the process of the energy flow system through the inductor-capacitor system, applying this principle to the biphasic TMS pulse.

Measuring Behavior of Impactor Penetrating through Polymer Sheet Based on Electromagnetic Induction

2016 ◽  
Vol 715 ◽  
pp. 122-127 ◽  
Author(s):  
Tadaharu Adachi ◽  
Masashi Osada ◽  
Keiko Watanabe
Keyword(s):  
Electromotive Force ◽  
Electromagnetic Induction ◽  
High Speed ◽  
Measuring Method ◽  
Video Camera ◽  
Calibration Data ◽  
Polymer Sheet ◽  
High Speed Video Camera ◽  
Measured Electromotive Force ◽  
Impactor Velocity

In the paper, the behavior of an impactor penetrating through a polymer sheet was measured using electromagnetic induction phenomena. First, electromotive forces generated in a coil were measured to decide the relation between the impactor velocity and the electromotive force when the impactor with an embedded neodymium magnet passed through a coil at several constant velocities. The intensity of the electromotive force was found to be proportional to the impactor velocity at each impactor position. The relation was used as the calibration data to calculate the velocity and position of the impactor. Next, penetration tests of polyvinyl chloride sheets were conducted with the coil set at the front of the sheet. The electromotive force generated in the coil was measured when the impactor penetrated through the sheet. The impactor velocity and position were calculated from the electromotive force with the calibration data. The validity of the measuring method was confirmed because the calculated results from the measured electromotive force agreed with the observed results by using a high speed video camera.

Experimental Investigation of Effectiveness of Smart Passive System for Seismic Protection of Building Structures

2008 ◽  
Vol 56 ◽  
pp. 355-362
Author(s):  
Hyung Jo Jung ◽  
Dong Doo Jang ◽  
Heon Jae Lee ◽  
Seok Jun Moon
Keyword(s):  
Electromagnetic Induction ◽  
Mr Damper ◽  
Shaking Table ◽  
Frame Structure ◽  
Seismic Protection ◽  
Semiactive Control ◽  
Building Structures ◽  
Passive System ◽  
Engineering Structures ◽  
Faraday’S Law

The newly developed smart passive system is based on a magnetorheological fluid (MR) damper, which is one of the most promising semiacitve control devices, and an electromagnetic induction (EMI) part, which is a power harvesting device from vibration of a structure according to Faraday’s law of electromagnetic induction. Numerical simulations recently conducted by the authors have verified that the smart passive system could be effective to reduce the structural responses in the cases of civil engineering structures such as buildings and bridges. On the other hand, the experimental validation of the system is not sufficiently carried out yet. In this study, therefore, a series of shaking table tests are conducted to experimentally investigate the effectiveness of the smart passive system for seismic protection of building structure. The model structure is a scaled six-story frame structure with the height of 3.5 m and the weight of about 8 ton. The smart passive system is installed between its base floor and the first floor. The responses of the structure are measured under several ground motions including scaled historic earthquake records. The preliminarily experimental results in the smart passive system case are compared with those in the MR damper-based semiactive control cases.

University students’ understanding of the electromotive force concept in the context of electromagnetic induction

2016 ◽  
Vol 37 (6) ◽  
pp. 065709 ◽  
Author(s):  
Kristina Zuza ◽  
Mieke De Cock ◽  
Paul van Kampen ◽  
Laurens Bollen ◽  
Jenaro Guisasola
Keyword(s):  
University Students ◽  
Electromotive Force ◽  
Electromagnetic Induction ◽  
Force Concept
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