1. Gauss’s Law

2. Electric Flux
Measure of the number of electric field lines passing through a surface.
For a uniform electric field
Non-uniform electric field

3. Calculate Flux
A square with an area of 5 m² has a surface normal of What is the flux through this surface if the square is embedded in a uniform electric field of ?

4. Closed Surface Consider the flux on a closed surface. Tp Bk Lf Rt FrBt

5. Gauss’ Law
Net electric flux through any closed gaussian surface is equal to the net charge inside divided by e0.

6. Point Charge Choose a sphere as your gaussian surface.
Electric field is perpendicular to the surface and of uniform strength at the surface. q

7. Line Charge Choose a cylinder as your gaussian surface.
Electric field is perpendicular to the walls and parallel to the end caps.

8. Sheet Charge Choose a box as your gaussian surface.
Electric field is perpendicular to the top & bottom, but parallel to the sides.

9. Volume Charge Choose a sphere as your gaussian surface.
Gaussian surface may be inside the volume. q

10. Conductors Electric field is zero inside a conductor
Any excess charge must be on the surface
Electric field leaves perpendicular to the surface.
Irregular shapes: more charge accumulates where the radius of curvature is smallest.
Near the surface

11. Irregular Conductors
How would you draw the electric field on the following conductors?