For an isolated conductor, the surface charge density around the surface is related to the surface curvature there. Generally speaking, the surface charge density is high where the curvature is large.

For an isolated conductor, the surface charge density around the surface is related to the surface curvature there. Generally speaking, the surface charge density is high where the curvature is large.

This is determined by the characteristics of charge distribution. Characteristics of charge distribution: charge is only distributed on the surface of conductor. A curved surface (1/R) is convex when its curvature is large, and a curved surface (1/R) is flat and concave when its curvature is small. The surface of a conductor is much more convex than flat or concave, so generally speaking, the surface charge density is high where the curvature is large.

Just as Mr. Wang upstairs said that "the surface charge density is directly proportional to the surface curvature, so the greater the curvature of the conductor surface, the greater the charge density" is equivalent to saying that "the greater the curvature, the greater the surface charge density, so the greater the curvature, the greater the surface charge density", just like I didn't say! Always makes people laugh like this!