What is electrostatic analogy?

For the comparison between constant electric field and static electric field, we can analyze the problem of field by analogy, and only replace the corresponding quantity according to the above table. By this method, the electrostatic field generated by static point charge or distributed charge is compared with the constant current field, and it can be seen that the physical quantities in the two fields have obvious symmetrical properties in two different occasions.

According to the analogy between two physical phenomena, observing and testing one physical phenomenon is a method to study another physical phenomenon. If there are physical quantities in two (or more) physical phenomena that can be described by the same mathematical equation, then there will be analogy between them, hence the name analogy method.

Extended data

Similar to the analysis of electrostatic field, the changes of normal and tangential components of current field at the interface are still discussed through basic properties such as divergence and curl. The normal component uses the divergence property, and the corresponding theorem is the continuity equation of current. The tangential component is still analyzed by zero curl of electric field.

There is no excess charge in the conductor, so the charge density is zero, so the divergence of current density in the conductor is zero (full current equation or current continuity principle), and the conclusion is that the normal component of current density is continuous.

At the same time, the electric field e of the constant current field is still a conservative field, and its curl is zero, so the nature of the electrostatic field is still that the tangential component of the electric field is still continuous.