Explain volume charge density. Write its unit.

Volume charge density, often denoted by the symbol ρ (rho), is a physical quantity used in electromagnetism to describe the distribution of electric charge within a given volume of space. It represents the amount of charge per unit volume. In other words, volume charge density tells us how much charge is present within a certain volume.

Mathematically, volume charge density (ρ) is defined as:

ρ = Q / V

Where:

ρ is the volume charge density.
Q is the total electric charge contained within the volume V.
V is the volume of the region in which the charge is distributed.
The SI unit of volume charge density is the coulomb per cubic meter (C/m³). In this unit, 1 C/m³ means that there is one coulomb (the unit of electric charge) of charge distributed within every cubic meter of the given volume.

So, the unit of volume charge density (ρ) is C/m³.