Electric Flux Density

Electric flux density, abbreviated as D, is the amount of electric flux passing through a given area per unit area.  In a vacuum, where there is no material influence, the electric flux density and the electric field are directly proportional and have the same direction.  However, in materials (such as dielectrics), the electric displacement field accounts for the polarization of the material and differs from the electric field.  Electric flux density is important in understanding the behavior of electric fields in different materials, including insulators, conductors, and dielectrics.

 

Electric flux density formula
\( D = \phi_E  \;/\; A  \)
Symbol	English	Metric
\( D \) = electric flux density	-	\(C\;/\;m^2\)
\( \phi_E \)  (Greek symbol phi) = electric flux	-	\(N-m^2\;/\;C\)
\( A \) = area cross-section of the surface	-	\(m^2\)

   

Electric flux density formula
\( D = \epsilon  \;  E  \)
Symbol	English	Metric
\( D \) = electric flux density	-	\(C\;/\;m^2\)
\(\epsilon\) (Greek symbol epsilon) = permittivity (the material through which the electric field passes)	-	\(m^2\)
\( E \) = electric field	-	\(m^2\)

 

Electric flux density formula
\( D = q  \;/\; 4 \; \; \pi \; R^2  \)
Symbol	English	Metric
\( D \) = electric flux density	-	\(C\;/\;m^2\)
\( q \)  = electric charge inside of surface A (single point charge)	-	\(A-s\)
\(\large{ \pi }\) = Pi	\(3.141 592 653 ...\)
\( R \) = q at distance R	-	\(m^2\)