Rho (greek letter, not sure on spelling)

[Bad-Wolf]

I don't quite understand how to use rho charge per volume. I understand the applications of lamda and sigma as sigma is useful Gauss's Law and lambda is easy when dealing with wires and such. However, how the hell do you use charge per volume? I mean charges only occupy the surfaces of conductors... What law or physical concept can I use to determine how a sphere with volume charge density rho would effect well anything.

Basically, what laws or tricks do I use when working with rho? How could a sphere have a volume charge density when all the charges are on the surface to begin with?

 

[UTDphysmace]

I believe charge per unit volume applies when you are dealing with an insulating object that has had a charge applied to it. As my prof would say, when you apply a charge to an insulating object, the charge stays where you put it. so if you have an insulating object with the charge evenly distributed throughout, it stays there, rather than moving to the surfaces, thus charge is equally distributed through the volume of the object.

please anyone correct me if I'm wrong.

 

[Moetasim]

Dear writer,

Thank you for your question about the use of rho charge per volume. Rho, or ρ, is a symbol used to represent volume charge density in physics. It is a measure of the electric charge per unit volume in a given region of space.

To understand how to use rho, it is important to first understand its definition and units. Volume charge density is defined as the amount of electric charge per unit volume, measured in coulombs per cubic meter (C/m³). This means that for a given volume, there is a certain amount of charge distributed within that volume.

One way to think about this is by considering a charged sphere. While it is true that charges on a conductor will primarily reside on the surface, there can also be a distribution of charges within the volume of the sphere. This is where rho comes into play. By knowing the volume of the sphere and the total charge it contains, we can calculate the charge per unit volume or the volume charge density.

In terms of laws or tricks to use when working with rho, one important concept is Gauss's law. This law states that the electric flux through a closed surface is equal to the charge enclosed by that surface divided by the permittivity of free space. In this case, the enclosed charge can be represented by rho, and by using Gauss's law we can determine the electric field at any point in space due to a charged object with a given volume charge density.

In summary, rho charge per volume is a useful concept in understanding the distribution of electric charge within a given volume. It can be applied in various situations, such as calculating electric fields or understanding the behavior of charged objects. I hope this helps clarify the use of rho in physics.