Practice question

**Independent action of charges** allows total force or field as vector sum. Geometry dictates distances to evaluation point, and resultant follows Σ k q_i/r_i², explaining zero field at symmetric centres for equal charges. The superposition principle allows the total electric field to be the vector sum of fields from individual charges, assuming each field is unaffected by others. This linearity stems from the nature of electrostatic forces, enabling independent analysis. Substituting values gives Superposition, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.