net electric flux from charge of electron

The electric flux through the top face ( ) is positive, because the electric field and the normal are in the same direction. Electric flux through the bottom face ( ) is negative, because is in the opposite direction to the normal to the surface. Notice that may also be written as, demonstrating that electric flux is a measure of the number of field lines crossing a surface.įigure 2.1.5 Electric flux through a cube, placed between two charged plates. Electric flux is a scalar quantity and has an SI unit of newton-meters squared per coulomb ( ).

We represent the electric flux through an open surface like by the symbol. The quantity is the electric flux through. If field lines pass through, then we know from the definition of electric field lines ( Electric Charges and Fields) that, or. To quantify this idea, Figure 2.1.2(a) shows a planar surface of area that is perpendicular to the uniform electric field. Again, flux is a general concept we can also use it to describe the amount of sunlight hitting a solar panel or the amount of energy a telescope receives from a distant star, for example. Similarly, the amount of flow through the hoop depends on the strength of the current and the size of the hoop. As you change the angle of the hoop relative to the direction of the current, more or less of the flow will go through the hoop. The numerical value of the electric flux depends on the magnitudes of the electric field and the area, as well as the relative orientation of the area with respect to the direction of the electric field.Ī macroscopic analogy that might help you imagine this is to put a hula hoop in a flowing river. Figure 2.1.1 The flux of an electric field through the shaded area captures information about the “number” of electric field lines passing through the area.

Net electric flux from charge of electron