Gauss' Law
Gauss' Law (a FUNDAMENTAL Law):
The net electric flux through any closed surface is proportional to the charge enclosed by that surface.
- How to Apply??
- The above eqn is TRUE always, but it doesn’t look easy to use
- It is very useful in finding E WHEN the physical situation exhibits massive SYMMETRY
- To solve the above eqn for E, you have to be able to CHOOSE a closed surface such that the integral is TRIVIAL
- Direction: surface must be chosen such that E is known to be either parallel or perpendicular to each piece of the surface
- Magnitude: surface must be chosen such that E has the same value at all points on the surface when E is perpendicular to the surface.
- Therefore: that allows you to bring E outside of the integral