Practice question

**Electric field** defined as E = F/q₀, force per unit positive test charge, unit N/C or V/m, direction along force on positive test charge. For point charge, E = k q/r² radially outward for q>0. Field lines start on positive and end on negative, density indicates strength. In electrostatic equilibrium, the electric field inside a conductor must be zero. If charges existed inside, they would create a field, causing further movement. Thus, charges redistribute to the surface, where they can maintain zero internal field due to their mobility. Substituting values gives Mobility, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.