Practice question

**Gauss's law** Φ = ∮ E·dA = q_enc/ε₀ is fundamental relation between flux and enclosed charge. For charge at centre of cube, total flux = q/ε₀ distributes equally over six faces, each receiving Φ/6, but total remains q/ε₀ irrespective of cube edge. Gauss’s law shows that the field inside depends only on enclosed charge. External charges induce surface charges on the conductor, but these adjust to cancel the external field inside, leaving it zero regardless of outside charges. Substituting values gives No enclosed charge, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.