First page Back Continue Last page Overview Image
- PHY102 Physics II © Dr.Cem Özdoğan
- For small A, E can be taken as constant over A. Thus, the flux of electric field for the Gaussian surface of Fig. 23-3 is
- Electric flux through a Gaussian surface is proportional to the net number of electric field lines passing through that surface.
- Fig. 23-3 A Gaussian surface of arbitrary shape immersed in an electric field. The surface is divided into small squares of area A. The electric field vectors E and the area vectors A for three representative squares, marked 1, 2, and 3, are shown.
- Now we can find the total flux by integrating the dot product over the full surface. The total flux through a surface is given by
- The net flux through a closed surface (which is used in Gauss’ law) is given by
- The loop sign indicates that the integration is to be taken over the entire (closed) surface. The SI unit for Φ is (N.m2/C).