Physics 201- Introduction to Electricity & Magnetism
September 18- Gauss' Law






  Electric Flux
  • It depends on the strength of the field
  • It depends on the surface size
  • It depends on the relative angle between the field and surface

All of this is summed up in the relationship:

The six figures show six different surfaces (viewed from the side) in uniform electric fields. (Much like figure 24-1, but viewed from the side.)   In each case the electric field is the same magnitude.  The surfaces are either of area A or 2A (indicated by the size of the facing edge).  The surfaces are perpendicular, parallel or 45o to the electric field.  Rank the six figures in order of increasing electric flux.  Be sure to indicate any ties.


Does our mathematical definition of the flux support our results?


q is the angle between the normal vector and the electric field.

If the angle doesn't change over the surface, then we can pull out the constants from inside the integral, making life much easier.
If you don't have this special case, then the integral is a real pain in the ass.


About the Course
Study Hints
Problem Solving
Homework- assignments & solutions
Miscellaneous links
About Dr. Jeff



Jeff Phillips
Loyola Marymount University
Fall 2002