Charge Distribution
Charge distribution refers to the arrangement of electric charges within a given space. It describes how the charges are distributed, whether evenly or unevenly, and can be represented by charge density. Understanding charge distribution is crucial in analyzing the behavior of electric fields and the interactions between charged particles.
3 Key excerpts on "Charge Distribution"
eBook - ePubElectromagnetics Explained
A Handbook for Wireless/ RF, EMC, and High-Speed Electronics
- Ron Schmitt(Author)
- 2002(Publication Date)
- Newnes(Publisher)
...When charge is placed onto the ball, the individual charges will immediately spread apart as far as possible because like charges repel each other. The upshot is that all the charge becomes concentrated at the surface. It’s like a bunch of people in a large room. If each person tries to avoid the rest, they will migrate to the walls of the room, like a “wallflower” at a high school dance. How quickly charges distribute themselves to the surface is proportional to the relaxation time of the material. In the present context, the relaxation time can be approximated as the dielectric constant (discussed later in the chapter) of the material divided by the conductivity of the material. The relaxation time specifies how freely charge can move in a material. For copper, the relaxation constant is Therefore, charge placed on a copper object will very quickly redistribute so that it all resides on the surface. The charge half-life of a material is about 0.7 times the relaxation time. An example will help illustrate this concept. If charge is somehow placed at the center of a metal ball, the charge will immediately start to migrate toward the surface. After a half-life in time (0.7 τ), half of the charge will have migrated away from the center. ELECTROSTATIC INDUCTION AND CAPACITANCE To understand capacitance, you need to first understand the process of electrostatic induction. For example, consider that you have a metal ball that is positively charged, near which you bring a neutral metal ball. Even though the second ball has overall neutrality, it still contains many charges. Neutrality arises because the positive and negative charges exist in equal quantities. When placed next to the first ball, the second ball is affected by the electric field of the charged ball. The charges of the second ball separate. Negative charges are attracted, and positive charges are repelled, leaving the second ball polarized, as shown in Figure 2.5...
eBook - ePubElectrical Engineering
Fundamentals
- Viktor Hacker, Christof Sumereder(Authors)
- 2020(Publication Date)
- De Gruyter Oldenbourg(Publisher)
...Through charge separation another electric field forms within the conductor, which counteracts the outer field. The charge redistribution is completed when the opposing field is equal to the outer field. The inside of the conductor is thus field free meaning that this space is shielded against the outer field (Faraday cage – charges on the metal surface). Figure 4.8: Electrostatic induction is the redistribution of electric charges in a conductor under the influence of an electric field. 4.4 Polarisation The redistribution of charges in the electric field does not only take place in electric conductors but also in electrically insulating materials. Due to the charge carriers being stationary in insulators, the electric charges can only be moved or twisted within their associated atom or molecule. Insulating materials have hardly any free electrons; charges are only moved slightly (weak induced voltage). Therefore, due to the impact of the electric field small, electric dipoles form on the previously neutral insulating material atoms. If charges are electrostatically separated from an originally neutral object, we talk about polarisation. There are two types of polarisation: Dielectric polarisation occurs with certain insulating materials. Within the molecules, charges are aligned. These molecules are called dipoles. Paraelectric polarisation : Insulating materials are already organised as dipoles. However, without an outer electric field, the electric effects cancel each other out due to the disordered thermal movement (a). If an outer field is applied, the dipoles align themselves according to their polarities (b). 4.5 The electric displacement flux Ψ Electric fields are the sum of all field lines. The fields occur due to the redistribution of charges; the sum of all field lines therefore is called displacement flux Ψ, which corresponds to the amount of separated charges...
eBook - ePub- Wai Kai Chen(Author)
- 2004(Publication Date)
- Academic Press(Publisher)
...2 Electrostatics Rodolfo E. Diaz, Department of Electrical Engineering, Ira A. Fulton School of Engineering, Arizona State University, Tempe, Arizona, USA 2.1. Introduction 2.1.1. Conventions 2.2. Sources and Fields 2.2.1. D Fields of Charge Distributions Using Gauss’s Law 2.2.2. First Alternative to Gauss’s Law: Integration over Charge Distributions 2.2.3. Second Alternative to Gauss’s Law: The Potential Function 2.3. Boundary Conditions and Laplace’s Equation 2.3.1. The Fields of Charged Conductors and the Method of Images 2.3.2. Laplace’s Equation and Boundary Value Problems 2.3.3. The Connection Between D, P, E, and ε 2.4. Capacitance 2.4.1. Capacitance of Various Configurations and Energy 2.4.2. Partially Filled Capacitors 2.4.3. Static Current Fields References 2.1 Introduction Electrostatics in its most restrictive sense is the specialization of Maxwell’s equations to a system whose sources are steady-state, time-invariant electric charges. Because the conservation of charge is implicit in this definition, the unifying principle of all the equations is the conservation of total electric flux. Therefore, electrostatics also properly includes steady-state conduction current problems. In this chapter, the fundamental relationship between source and field is between the electric charge q (measured in coulombs) and the electric flux density D (measured in coulombs per meter squared) because that relationship has the form of a conservation law. The electric field E (measured in volts per meter) is introduced with the concept of the electrostatic potential Φ (measured in volts) as the quantity involved in the dynamics of electrostatic systems (i.e., their interaction forces and energies). In this way, ε (measured in farads per meter), the permittivity of the material medium through which the flux traverses, appears as a proportionality constant that gauges the amount of energy stored in a given electrostatic system...
