# What is the difference between electric charge and electric flux?

What is the difference between electric charge and electric flux? According to my knowledge electric flux is nothing but electric charge enclosed by the closed surface.

• Electric flux describes how the electric field flows through a (perhaps imaginary) surface. – Dargscisyhp Sep 12 '14 at 2:39
• I'd argue your knowledge is a little flawed. What does your textbook tell you of these two items? – Kyle Kanos Sep 12 '14 at 2:39
• This could be an issue of textbooks using the word "flux" to refer to the integrated electric field piercing a surface. This might come up in discussions of Gauss's law, in which case it would be easy to mentally associate "flux" and "charge". Of course, this is all just due to the degeneracy of the word "flux", which means both "area integral of magnetic field" and "area integral of any vector". – DanielSank Sep 18 '14 at 19:23

The electric flux is only related to charge when you're considering a closed surface for it. Gauss's law tells you about the connection between charge and flux through closed surfaces only! Which is: $$\oint_{S_{closed}}\mathbf E.d\mathbf a = \frac Q{\epsilon_0}$$ Keep in mind that in general, the electric flux through any open surface is also perfectly well defined, and does not have a direct connection to charge: $$\Phi \equiv \int_S\mathbf E.d\mathbf a$$ The circle in the integral symbol for Gauss's law is there for a reason!

Wikipedia>

Electric charge: Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field.

Electric flux: In electromagnetism, electric flux is the rate of flow of the electric field through a given area. Electric flux is proportional to the number of electric field lines going through a virtual surface.

This could have been easily resolved by a simple wikipedia search, I strongly advice you to do atleast preliminary search on raised questions before asking them here as unresearched questions attract negative reputation.

The electric flux passing through any closed surface area is equal to the total charge enclosed by the respectiva surface.This is generliasation of so called Gauss's law.

Take this as the definition of the electric flux going through some surface S in some electric field E $$\Phi_E = \int_S {\bf E} \cdot d { \bf a}$$

This says that to find the flux on the surface we simply add up the electric field at each point on the surface.

On the other hand this is Gauss's law:

$$\int_S {\bf E} \cdot d { \bf a} = \frac{Q}{\epsilon_0}$$

Where Q is the total charge enclosed by the surface S.

From these two equations we can quickly deduce that: $$\frac{Q}{\epsilon_0}=\Phi_E$$ So electric flux and charge are very much related but not quite the same thing.