Definition:Electric Charge Density

Definition
Let $A$ be a point in space in which an electric field acts.

Let $\delta V$ be a volume element containing $A$.

The (electric) charge density $\map \rho {\mathbf r}$ at $A$ is defined as:

where:
 * $Q$ denotes the electric charge within $\delta V$
 * $\mathbf r$ denotes the position vector of $A$.

Thus the electric charge density is the quantity of electric charge per unit volume, at any given point in that volume:

Also known as
Electric charge density can also be referred to as charge density if it is understood that electric charge is the quantity under discussion.

Also see

 * Definition:Surface Charge Density
 * Definition:Linear Charge Density