Question

derive an expression for electric field intensity at distant r from a point chage q.

Answer 1

Answer:

electric field=q×q/r²

where r is distance

Answer 2

Answer:

Let us consider an isolated point charge of +q coulomb placed at point O in medium of dielectric constant K. This point charge develops an electric field and we want to find out the intensity of this field at point P at a distance r from it. For this let us consider a point test charge q o at point P.