Cornell Notes — Full Topic: Electrostatics — Notes | NoteTube

Cue / Question	Notes
What are the three properties of electric charge?	Conservation (constant in isolated system), Quantization (q = ne), Additive (algebraic sum)
State Coulomb's law	F = kq_{1}q_{2}/ $r^{2}$ ; k = $9 \times 10^{9}$ N $m^{2}$ / $C^{2}$ ; [F] = [M $LT^{-2}$ ]
What is electric field?	E = F/q_{0} = kQ/ $r^{2}$ ; [E] = [M $LT^{-3}$$A^{-1}$ ]; unit: N/C or V/m
What is a dipole moment?	p = q·2l; direction: −q → +q; [p] = [ATL]; unit: C·m
State Gauss's law	Φ = q_enc/ε_{0}; Φ = ∮E·dA; unit: V·m
E inside a conductor?	Always zero — free charges reside only on the surface
E inside a uniformly charged insulator at r < R?	E = kQr/ $R^{3}$ — increases linearly with r
Axial vs equatorial dipole field ratio?	E_axial = 2kp/ $r^{3}$ ; E_eq = kp/ $r^{3}$ ; ratio = 2:1
Capacitor with dielectric, battery connected?	V constant; C increases by K; U increases by K
Capacitor with dielectric, battery disconnected?	Q constant; C increases by K; V and U decrease by K

Summary: Electrostatics describes electric charge, forces (Coulomb's law), fields (including Gauss's law applications), dipole behavior, and capacitors. Key NEET focus: E inside conductors vs insulators, dipole field ratio (2:1), and the battery connected vs disconnected dielectric insertion scenario.