Point Charge (on Axis)
The Point Charge (on Axis) node adds a point source to 2D axisymmetric components. The point charge represents an electric displacement field flowing out of the point.
Add a contribution as a Harmonic Perturbation by right-clicking the parent node or clicking Harmonic Perturbation in the Physics toolbar. For more information see Harmonic Perturbation — Exclusive and Contributing Nodes in the COMSOL Multiphysics Reference Manual.
Point Selection
Beware that constraining the potential on points usually yields a current outflow that is mesh dependent.
Point Charge (on Axis)
Enter a value or expression to apply a Point charge QP (SI unit: C) to points on an axis. This source represents an electric displacement field flowing out of the point. The default is 0 C.
Point Charge and Line Charge (Out-of-Plane)