Electric flux facts for kids
Electric flux is a way to measure how much of an electric field passes through a surface. Imagine an electric field like invisible lines of force. Electric flux tells you how many of these lines go through a certain area.
Think of it like water flowing through a net. The amount of water passing through the net depends on how strong the water flow is, the size of the net, and how the net is angled towards the flow. Electric flux works in a similar way with electric fields.
To find the electric flux through a tiny part of a surface, you multiply the strength of the electric field by the area of that tiny part. You also need to consider the angle at which the electric field hits the surface. If the field hits the surface straight on, the flux is strongest. If it just skims along the surface, the flux is zero.
To find the total electric flux over a whole surface, you add up the flux from all the tiny parts of that surface.
Gauss's Law and Electric Flux
A very important rule about electric flux is called Gauss's law. This law says that if you have a closed surface (like a balloon or a box), the total electric flux passing through that surface depends only on the total electric charge inside the surface.
It doesn't matter what charges are outside the surface; they don't affect the total flux through the closed surface. However, charges outside can still affect the electric field itself at any point on the surface.
Gauss's law is always true. But it's easiest to use for calculations when the electric field has a simple, symmetrical shape. For example, it works well for fields around a sphere or a long cylinder. For more complex shapes, you usually need a computer to do the math.
Units of Electric Flux
Electric flux has specific units to measure it. In the SI system, electric flux is measured in volt metres (V m). You can also express it as newton metres squared per coulomb (N m2 C−1).
The basic units for electric flux are kg•m3•s−3•A−1.
Related pages
See also
In Spanish: Flujo eléctrico para niños
