Q 12-01-017NEETJEE MainEasy
The electric field just outside a large uniformly charged plane sheet of surface charge density $\sigma$ is
Answer: (A) $\dfrac{\sigma}{2\epsilon_0}$
Concept. Gauss's law with a pillbox through a thin sheet: flux leaves through both faces.
Step 1. Apply. $2EA = \dfrac{\sigma A}{\epsilon_0} \Rightarrow E = \dfrac{\sigma}{2\epsilon_0}$. (Near a conductor's surface it would be $\dfrac{\sigma}{\epsilon_0}$.)
Answer. $\dfrac{\sigma}{2\epsilon_0}$ (Option A).
Solution by Sreeraj P, M.Sc Physics