B Electric flux density and confusion about units

AI Thread Summary
Electric flux density is defined as electric flux per unit area, typically expressed in N/C, but it can also be represented using the formula D = εE, leading to the unit C/m². This creates confusion regarding the dimensional consistency between the two interpretations. The discussion clarifies that if D is termed as flux density, the corresponding flux is that of the displacement field, Φ_D = ∫ D·dS. It is also noted that Φ_D relates to the electric flux Φ_E through the equation Φ_D = εΦ_E. Understanding these relationships helps resolve the unit discrepancies.
sunil36
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My general understanding of electric flux density is 'electric flux per unit area'. This gives the SI unit N/C. But According the formula of electric flux density, D=eplison*E, the SI unit is C/m^2. How come the dimension in both cases not matching if both are true?
 
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I think there's some terminological confusion. If you're planning on calling ##\vec D## the flux density then the corresponding flux is the flux of the displacement field, ##\Phi_D=\int \vec D\cdot d\vec S##. That's related to the flux we discussed in your other thread, ##\Phi_E=\int \vec E\cdot d\vec S##, as ##\Phi_D=\varepsilon \Phi_E##. I think that should sort out the units.
 
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