Which one of the following equations is not Maxwell's equation for a static electromagnetic field in a liner homogeneous medium?
1
\(\nabla \cdot \overrightarrow B = 0\)
2
\( \nabla \times \overrightarrow D = 0\)
3
\(\oint {\overrightarrow B \cdot dl = ({\mu _0}/4\pi )I} \)
4
\(\nabla(\nabla \cdot \overrightarrow A)- (\nabla^2 \overrightarrow A)= {\mu _0}J\)