The divergence of the vector flux density A is the outflow of flux from a small _________ surface per unit volume as the volume _________.

The correct answer is option 1):(closed, shrinks to zero)

Concept:

 Divergence of electric flux density using Maxwell’s equation is given by 

\(\nabla \cdot \vec D = div\;\vec D = \rho v\)

 \(\vec D\) = electric flux density in c/m2 &  volume charge density in c/m3

Thus divergence of electric flux density results in volume charge density

In the given diagram, the divergence of the electric field is zero when the number of electric fields emerging from the tube is equal to incoming field lines.

The divergence of the vector flux density A is the outflow of flux from a small closed surface per unit volume as the volume