Question

What is the point charge? Explain with example and how it is obtained?

Answer 1

The electric field of a point charge can be obtained from Coulomb's law:

The electric field from any number of point charges can be obtained from a vector sum of the individual fields. A positive number is taken to be an outward field; the field of a negative charge is toward it.

This electric field expression can also be obtained by applying Gauss' law.