Gauss’s law: flux through a sphere around a point chargeगाउस नियम: बिंदु आवेश को घेरे गोले से फ्लक्सGauss’s law: flux through a sphere around a point charge

NCERT Fig 1.22 · Class 12 Physics · Chapter 1 · interactive diagram

Parts and what they mean

• Point charge +q at the centre (केंद्र पर बिंदु आवेश +q) — The only charge enclosed.
• Gaussian surface: sphere of radius r (गाउसीय पृष्ठ: त्रिज्या r का गोला) — An imaginary closed surface. On it E has the same size everywhere and is along the outward normal.
• Field E (radially outward) (क्षेत्र E (त्रिज्यतः बाहर)) — E = q/(4πε₀r²) at every point of the sphere.
• Area element ΔS (क्षेत्रफल अवयव ΔS) — Flux through it: Δφ = E ΔS (E parallel to n̂). Adding all: φ = E × 4πr² = q/ε₀.
• Outward normal n̂ (बाहरी अभिलंब n̂) — For a closed surface we always take the outward normal.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 1.22. Report a mistake