Electric Fields CH22

Electric field strength definition

Force experienced per unit positive charge at a point.

electric field strength equation

E = f/Q

SI unit for electric field strength

NC^-1

Coulomb’s law definition

the electrostatic force between 2 point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between their centres.

Coulomb’s law equation

F = Qq/4ne0r² (F = electrostatic force between charges, Q = charge 1, q = charge 2, e0 = permittivity of free space (8.85×10-12Fm^-1), r = distance between centres of two charges

epsilon nought

permittivity of free space ( a measure of how much an electric field can pass through empty space)

electrostatic potential equation

q/4ne0r² (q = magnitude of electric charge, e0 = permittivity of free space, 4n = spherical symmetry of electric field, r = distance from charge to point being evaluated)

Electric field between parallel plates equation

E = v/d

Capacitance between parallel plates

C = epsilonA / d

Capacitance definition

the charge stored per unit potential difference across a capacitor