15.4: Maxwell's Second Equation
- Page ID
- 6214
Unlike the electrostatic field, magnetic fields have no sources or sinks, and the magnetic lines of force are closed curves. Consequently the surface integral of the magnetic field over a closed surface is zero, and therefore
\[ \text{div} \, \textbf{B} = 0 \tag{15.4.1} \label{15.4.1}\]
or, in the nabla notation
\[ \boldsymbol{\nabla} \cdot \textbf{B} = 0 \tag{15.4.2} \label{15.4.2}\]
This is the second of Maxwell's equations.