Gausss Law Electric Flux Measure of the number

Gauss’s Law

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

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 ?

Closed Surface • Consider the flux on a closed surface. Tp Lf Bk Fr Bt Rt

Gauss’ Law • Net electric flux through any closed gaussian surface is equal to the net charge inside divided by e 0.

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

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

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

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

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

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