Where \ varepsilon \ equiv \ varepsilon _ r \ varepsilon _ 0, \ varepsilon _ 0 is the electric constant, and \ rho _ E is a charge density external ( logically, not spatially ) to the medium.
12.
Where is the electron charge, is the position of the electron ( } } is the magnitude of the position ), the potential term is due to the Coulomb interaction, wherein is the electric constant ( permittivity of free space ) and
13.
The physical constant, commonly called the "'vacuum permittivity "', "'permittivity of free space "'or "'electric constant "', is an ideal, ( baseline ) physical constant, which is the value of the absolute dielectric permittivity of classical vacuum.
14.
My understanding of WP : NAME is that, in such cases, our longstanding policy is to use the most common unambiguous name, but a couple of users ( including Brews ) feel we should promote the term preferred by standards organizations and have been changing all the links in wikipedia to point to electric constant.
15.
There are many physical constants in science, some of the most widely recognized being the speed of light in vacuum " c ", the gravitational constant " G ", Planck's constant " h ", the electric constant " ? " 0, and the elementary charge " e ".
16.
Where " ? " is the charge density, which can ( and often does ) depend on time and position, " ? " 0 is the electric constant, " ? " 0 is the magnetic constant, and "'J "'is the current per unit area, also a function of time and position.
17.
This relation is reflected in Coulomb's law, which can be used to calculate the force acting on two charges q _ 1 and q _ 2 separated by a distance r by using the dielectric constant \ varepsilon _ r ( also called relative static permittivity ) of the medium in the denominator of the equation ( \ varepsilon _ 0 is an electric constant ):
18.
You have to make sure the physical laws are still obeyed, for example, { c _ 0 } ^ 2 \, \ epsilon _ 0 \, \ mu _ 0 = 1, ( those are the speed of light, electric constant, vacuum permeability, in that order ), so if you change the electric constant, you have to change either the speed of light, or the permeability to compensate.
19.
You have to make sure the physical laws are still obeyed, for example, { c _ 0 } ^ 2 \, \ epsilon _ 0 \, \ mu _ 0 = 1, ( those are the speed of light, electric constant, vacuum permeability, in that order ), so if you change the electric constant, you have to change either the speed of light, or the permeability to compensate.
