Electrostatic Potential and Capacitance

Electric potential at a point

Electric potential at a point is the work done per unit positive charge in bringing it from infinity to that point. V = W/q₀ = (1/4πε₀) × (q/r) for a

For an electric dipole with moment

For an electric dipole with moment p = q×2l, the potential at distance r and angle θ is V = (p cosθ)/(4πε₀r²). On axial line: V = ±p/(4πε₀r²), on equa

Electric field is the negative gradient

Electric field is the negative gradient of potential: E = -dV/dr or E = -(VB - VA)/d for uniform fields. This means electric field points from higher

Capacitance C = Q/V is

Capacitance C = Q/V is the ability of a conductor system to store charge per unit potential difference. For parallel plate capacitor: C = ε₀A/d, for s

Series

Series: 1/Cs = 1/C₁ + 1/C₂ + 1/C₃ (same charge, different voltages), Parallel: Cp = C₁ + C₂ + C₃ (same voltage, different charges). Series reduces tot