Q 12-01-004NEETNEET 2023Top questionEasy
If $\displaystyle\oint_S \vec{E}\cdot d\vec{S} = 0$ over a surface, then :
Answer: (A) the number of flux lines entering the surface must be equal to the number of flux lines leaving it.
Concept. Gauss's law: zero net flux means zero enclosed charge; it says nothing about the field being zero or uniform.
Step 1. Interpret. Zero net flux means every field line entering the surface also leaves it. The field need not be constant or uniform, and charges may lie outside.
Answer. The number of flux lines entering the surface must be equal to the number leaving it (Option A).
Solution by Sreeraj P, M.Sc Physics