Gauss's Law (Physics)

Recall cards on electric flux and Gauss's law. Electric flux: what it measures, its definition as the dot product of the electric field with an area vector, the symbol Phi, the unit N*m^2/C, its scalar nature, the area vector of flat and closed surfaces, the E*A*cos(theta) form for a uniform field, when flux is maximum or zero, the surface-integral form for a nonuniform field, the exit-positive/enter-negative sign convention, and why the net flux through a surface enclosing no charge is zero. Gauss's law: the statement that net flux equals enclosed charge over epsilon_0, its integral form, the meaning of q_enc, the Gaussian surface, that E is the total field from all charges, why outside charges add zero net flux, why the flux is independent of surface shape, the equivalence to Coulomb's law, the point-charge sphere result, and the role of superposition. Applying Gauss's law: identifying symmetry, matching the Gaussian surface to it, the spherical, cylindrical, and planar symmetry cases, and the field results for a sphere inside and out, an infinite line E = lambda/(2*pi*epsilon_0*r), an infinite plane E = sigma/(2*epsilon_0), parallel plates, and a spherical shell. Conductors in electrostatic equilibrium: the definition, conduction electrons, why the interior field is zero, why excess charge sits on the outer surface, the perpendicular field just outside E = sigma/epsilon_0, cavity induction, charge concentration at sharp points, and electrostatic shielding.