# What do you mean by free charge density and bound charge density?

## What do you mean by free charge density and bound charge density?

A free charge is not bound to the nucleus and can have any energy from zero. A bound charge, on the other hand, is bound to the nucleus and can have only quantized energies. The energy possessed by it is both potential and kinetic in nature with potential energy being greater always.

What is meant by surface charge?

Surface charge is a two-dimensional surface with non-zero electric charge. Surface charge emits an electric field, which causes particle repulsion and attraction, affecting many colloidal properties. Surface charge practically always appears on the particle surface when it is placed into a fluid.

What affects surface charge density?

Results show that pH and electric field can affect the surface charge density of glass and OTS surfaces immersed in saline solutions and DI water. The mechanisms of the effect of pH and electric field on the surface charge density are discussed.

### What is the unit of surface charge density?

Surface charge density (σ) is the quantity of charge per unit area, measured in coulombs per square meter (C⋅m−2), at any point on a surface charge distribution on a two dimensional surface.

What is free current and bound current?

Bound charge is simply the charge due to polarization, and the free charge is the other (i.e. non-bound) charge.

What is the symbol of surface charge density called?

σ
Surface charge density (σ) is the quantity of charge per unit area, measured in coulombs per square meter (C⋅m−2), at any point on a surface charge distribution on a two dimensional surface.

## How is surface charge density measured?

Surface charge density is a measure of how much electric charge is accumulated over a surface. It is calculated as the charge per unit surface area. If q is the charge and A is the area of the surface, then the surface charge density is given by; σ=qA, The SI unit of surface charge density is Cm–2.

What is the definition of surface charge density?

The charge density is the measurement for the accumulation of the electric charge in a given particular field. It measures the amount of electric charge as per the given dimensions. Dimensions may be the length, area or volume of the electric body.

Why is the bound volume charge density the negative sign?

Using the divergence theorem, the bound volume charge density within the material is The negative sign arises due to the opposite signs on the charges in the dipoles, one end is within the volume of the object, the other at the surface. A more rigorous derivation is given below.

### How is the bound charge of a dielectric determined?

Bound charge The bound surface charge is the charge piled up at the surface of the dielectric, given by the dipole moment perpendicular to the surface: where s is the separation between the point charges constituting the dipole, is the electric dipole moment,

How is the charge density measured in electromagnetism?

In electromagnetism, charge density is the amount of electric charge per unit length, surface area, or volume. Volume charge density (symbolized by the Greek letter ρ) is the quantity of charge per unit volume, measured in the SI system in coulombs per cubic meter (C⋅m −3), at any point in a volume. 