Question

HI, can anyone explain the relationship between D (electric field density) ∮S D⋅dA=Q(A) and electric flux density, phi, ∮SE⋅dA=Q(A)/εo?

Answer 1

\[\mathbf{D}=\frac{\mathbf{E}}{\epsilon_0}+\mathbf{P}\] so simply solve for E here and integrate and you have the relationship. It turns out to be the total free charge plus bound charge.

Answer 2

Also note that in free space they are effectively, though not dimensionally, the same.

Answer 3

Thanks a lot!