Concepts and Misconceptions In Physics - Can We Define Volume Charge Density Due To A Point Charge?
All the charge distributions are approximated to the volume charge distribution.Be it a discrete,line or surface charge distribution, charge will occupy some volume. But,depending on the geometry,sometimes we approximate the charges to point charges,line charges or surface charges. We can express any charge distribution as a volume charge distribution in terms of Dirac Delta Function. The volume charge density of a point charge is simply expressed as the product of the charge and the Dirac delta function defined at the location of the point charge.