Gauss’s law for magnetismचुंबकत्व के लिए गाउस नियमGauss’s law for magnetism

NCERT Fig 5.5 · Class 12 Physics · Chapter 5 · interactive diagram

Parts and what they mean

• Closed surface S (बंद पृष्ठ S) — It encloses the N pole. Counting the computed lines: 12 leave and 12 enter — the net magnetic flux is zero.
• Area element ΔS (क्षेत्रफल अवयव ΔS) — A tiny patch of the surface; its vector points outward, normal to the surface.
• Field B at the patch (टुकड़े पर क्षेत्र B) — Flux through the patch: Δφ_B = B·ΔS (positive where lines leave, negative where they enter).
• Field lines (क्षेत्र रेखाएँ) — Closed loops: every line that leaves a closed surface must come back in somewhere.
• Lines inside the magnet (चुंबक के अंदर रेखाएँ) — They enter the surface through the inside of the magnet — that is why no net flux leaves even though the N pole is inside.
• N pole (उत्तरी ध्रुव) — Not a “magnetic charge”: you cannot have N without S.
• S pole (दक्षिणी ध्रुव) — Lines re-enter the magnet here.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 5.5. Report a mistake