Electric field at a point due to a uniformly charged infinite plane sheet is
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → independent of the distance from the sheet
Applying Gauss's law to a cylinder that crosses the sheet, the flux leaves only through the two flat faces, each of area \( A \), and the charge enclosed is \( \sigma A \).
\( \displaystyle 2EA = \frac{\sigma A}{\varepsilon_0} \;\Rightarrow\; E = \frac{\sigma}{2\varepsilon_0} \)
The distance from the sheet does not appear, so the field is independent of the distance. The field lines of an infinite sheet are parallel, so they do not spread out as one moves away.
NCERT (2026-27):
Field Due to a Uniformly Charged Infinite Plane Sheet – “Let σ be the uniform surface charge density of an infinite plane sheet (Fig. 1.27).”
Field Due to a Uniformly Charged Infinite Plane Sheet – “… Note that the above application of the Gauss’ law has brought out an additional fact: E is independent of x also.”