Electrostatics

Gauss' law (∮E⃗·ds⃗ = q/ε₀)

Gauss' law (∮E⃗·ds⃗ = q/ε₀) is used to find electric field for symmetric charge distributions: uniformly charged sphere (E = q/4πε₀r² outside, E = 0 i

Electric potential V = U/q represents

Electric potential V = U/q represents work done per unit charge to bring a charge from infinity. For point charge: V = q/4πε₀r. Potential energy U = q

For electric dipole with moment p⃗

For electric dipole with moment p⃗, potential at distance r is V = (1/4πε₀)(p cos θ/r²). On axial line (θ = 0°): V = p/4πε₀r². On equatorial line (θ =

Surfaces where electric potential is constant

Surfaces where electric potential is constant. No work is done in moving charge along these surfaces. Electric field is always perpendicular to equipo

Conductors have free charges that redistribute

Conductors have free charges that redistribute to make E = 0 inside and constant potential throughout. Insulators have bound charges. In conductors: (