Book Review: Electric Charge and Electric Current Resistance and Ohm's Law Capacitance and Capacitors Introduction to A.C. Machines

1971 ◽  
Vol 9 (2) ◽  
pp. 151-152
Author(s):  
K. Fletcher
Keyword(s):  
Electric Current ◽  
Electric Charge ◽  
Ohm’S Law ◽  
Ohm's Law ◽  
Current Resistance

scholarly journals Time evolution of electric fields and currents and the generalized Ohm's law

2005 ◽  
Vol 23 (4) ◽  
pp. 1347-1354 ◽  
Author(s):  
V. M. Vasyliūnas
Keyword(s):  
Electric Field ◽  
Electric Current ◽  
Time Evolution ◽  
Time Scales ◽  
Current Density ◽  
Time Derivative ◽  
Electron Plasma ◽  
Displacement Current ◽  
Ohm’S Law ◽  
Ohm's Law

Abstract. Fundamentally, the time derivative of the electric field is given by the displacement-current term in Maxwell's generalization of Ampère's law, and the time derivative of the electric current density is given by the generalized Ohm's law. The latter is derived by summing the accelerations of all the plasma particles and can be written exactly, with no approximations, in a (relatively simple) primitive form containing no other time derivatives. When one is dealing with time scales long compared to the inverse of the electron plasma frequency and spatial scales large compared to the electron inertial length, however, the time derivative of the current density becomes negligible in comparison to the other terms in the generalized Ohm's law, which then becomes the equation that determines the electric field itself. Thus, on all scales larger than those of electron plasma oscillations, neither the time evolution of J nor that of E can be calculated directly. Instead, J is determined by B through Ampère's law and E by plasma dynamics through the generalized Ohm's law. The displacement current may still be non-negligible if the Alfvén speed is comparable to or larger than the speed of light, but it no longer determines the time evolution of E, acting instead to modify J. For theories of substorms, this implies that, on time scales appropriate to substorm expansion, there is no equation from which the time evolution of the current could be calculated, independently of ∇xB. Statements about change (disruption, diversion, wedge formation, etc.) of the electric current are merely descriptions of change in the magnetic field and are not explanations.

scholarly journals A new understanding of the origin of electric current

2021 ◽  
Vol 34 (4) ◽  
pp. 591-595
Author(s):  
Wei Fan
Keyword(s):  
High Temperature ◽  
Electric Current ◽  
Electric Charge ◽  
High Temperature Superconductivity ◽  
Theoretical Explanation ◽  
Pressure Potential ◽  
Electron Momentum ◽  
Electron Orbital ◽  
Potential Pressure ◽  
Current Resistance

Because charge, current, resistance, and voltage are understood based on the perspective of electricity, they can describe various electrical phenomena well, but they cannot explain their origins. Therefore, this article attempts to propose a new understanding of these phenomena from the perspective of mechanics to obtain a feasible way of explaining their origin and to solve problems that cannot be explained from the perspective of electricity. Specifically, this paper attempts to explain the origin of electric charge to obtain a new understanding of the origin of current and to obtain a new understanding of voltage and resistance by explaining the origin of current. Finally, from the perspective of mechanics, the origin of charge can be understood as a manifestation of electron momentum, the origin of current can be understood as a momentum flow, the origin of resistance can be understood as a momentum resistance, and the origin of voltage can be understood as a potential pressure (potential difference) of electron orbital potential. This new understanding of the origin of current from a mechanical perspective can provide a new theoretical explanation for high-temperature superconductivity.

Basic Electronics Theory for the Practicing Clinician

2010 ◽  
Vol 20 (2) ◽  
pp. 47-54
Author(s):  
Richard D. Andreatta
Keyword(s):  
Force Fields ◽  
Electrical Equipment ◽  
Correct Interpretation ◽  
Ohm’S Law ◽  
Basic Circuit ◽  
Basic Concepts ◽  
Ohm's Law ◽  
Instrumental Approaches ◽  
Current Resistance ◽  
Electrical Theory

For speech and hearing professionals who rely on and use electrical equipment to record and manipulate human biosignals, a poor appreciation of basic electrical theory may (a) inhibit their capacity to use novel instrumental approaches creatively and/or (b) prevent the correct interpretation of instrumental outputs. The purpose of this paper is to provide the practicing clinician with a non-mathematical tutorial on select topics of electricity, including force fields, voltage, current, resistance, Ohm's Law, and basic circuit configurations. The author's intent is directed toward demystifying basic concepts and principles of electricity, allowing the reader to feel more comfortable dealing with electrical applications in the workplace.

scholarly journals Use of filtration and electricity analogy in simulation of underflooding protection in urban construction

2021 ◽  
Vol 18 (4) ◽  
pp. 450-462
Author(s):  
V. I. Sologaev
Keyword(s):  
Electric Current ◽  
New Technologies ◽  
Darcy’S Law ◽  
Underground Water ◽  
Darcy's Law ◽  
Water Filtration ◽  
Ohm’S Law ◽  
Balance Principle ◽  
Urban Construction ◽  
Ohm's Law

Introduction. The fight against underflooding remains an urgent problem. The application of the analogy between water filtration and electric current has the goal of protecting the environment, built-up areas and, in particular, highways in cities from underflooding. Writing Ohm’s law similarly to Darcy’s filtration law, we achieve a better match to their analogy. This, in turn, makes it possible to develop new technologies for protection against underflooding in urban construction, for example, electroosmotic dewatering and its modeling. Such technologies make it possible to drain clayey soils.Methods and materials. Darcy’s law, Ohm’s law and the law of electroosmotic filtration are considered together. A methodology for modelling construction dewatering is given, taking into account the combined effect of the two physical laws of water filtration and electroosmosis, optimally combining the high-altitude geometric arrangement of drainage bases and contact electrodes. The options for draining clay soil under the action of an electric field are presented. With the combined use of gravitational forces and electric direct current forces in the drained soil, the total filtration rate is the sum of the Darcy’s law component and another component of the water velocity – electroosmotic filtration. An additional feature of joint modelling in a porous medium of water filtration and electroosmosis is that the mass of the water-resistant part of the soil and its part related to the dielectric may not coincide. This complexity of the model is overcome by dividing it into modules, which can then be combined in compliance with the balance principle, stitching modules along the boundaries. To continue the scientific discussion, a short but informative overview of international publications on the topic under consideration is given.Discussion. The methodology for complex calculation and modelling of the joint processes of water filtration in soils, the flow of electric current and electroosmotic filtration can find useful application in the development of effective protection against underflooding in urban construction. a sequence of algorithmic modelling steps is recommended. initially, it is recommended to run rough spreadsheet simulations on personal computers and mobile phones. next, a different modelling approach should be applied. based on the initial rough models of the previous step, it is necessary to write the algorithms in the programming language. the compiled model of the investigated filtration and electroosmosis processes will significantly increase the reliability of the design of protection against underflooding.conclusion. a comparison is made of the joint use of construction dewatering means of different physical essence, with simultaneous processes of gravitational filtration of underground water and passing a direct electric current through the drained soil, which causes an additional effect of electroosmosis. it is proposed to apply in a new way the analogy of water filtration and electric current in order to achieve more effective results of engineering activities by modeling protection against underflooding of building areas, ensuring the safety of urban construction when the level of groundwater rises.

Motion of Electron Gas and the Induced Nanofilm Electromigration

2007 ◽  
Author(s):  
Bing-Yang Cao ◽  
Qing-Guang Zhang ◽  
Zeng-Yuan Guo
Keyword(s):  
Kinetic Energy ◽  
Electric Current ◽  
Current Density ◽  
Electron Gas ◽  
Electric Current Density ◽  
Electric Resistance ◽  
Energy Effect ◽  
Ohm’S Law ◽  
Ohm's Law ◽  
Electron Wind

Understanding how electron gas moves and induces electromigration is highly desirable in micro- and nano-electronic devices. Based on introducing some novel concepts of electron gas momentum, kinetic energy and resisting force, we establish the continuum, momentum and energy conservation equations of the electron gas in this paper. Through analyzing the control equations, the Ohm’s law can be derived if the inertial force or the kinetic energy of the electron gas is ignored. Thus, the Ohm’s law is no longer applicable if the variation of the electron gas momentum is too large to be ignored. For instance, the kinetic energy variation can not be ignored for the electron gas with a high velocity flowing along the conductor with variable cross-sections. Under such conditions, the electric resistance of the section-variable conductors is a function of the electric current density and direction, which is referred to as a kinetic energy effect on the electric resistance. Based on the control equations of the electron gas motion, the electron wind force and the kinetic energy can also be calculated. The kinetic energy transferred from the electron wind to metallic atoms increases greatly with the increasing electric current density. It may be comparable with the activated energy of the metallic atoms in nanofilms. Thus, the electromigration induced by the electron wind can be regarded as another kind of kinetic energy effect of the electron gas, i.e. kinetic energy effect on the electromigration.

OHM'S LAW IS THE GENERAL LAW OF EXACT SCIENCES

2016 ◽  
Vol 72 (7) ◽  
Author(s):  
Alexander Alexandrovich Antonov
Keyword(s):  
Ohm’S Law ◽  
General Law ◽  
Ohm's Law
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