Question

A charge \(Q\) is uniformly distributed over a large plastic sheet. The electric field at a point \(\text{P}\) close to the centre of the sheet is \(10~\text{N/C}\). If the plastic sheet is replaced by a copper sheet of the same geometrical dimensions and carrying the same charge \(Q\), the electric field at the point \(\text{P}\) will become

Answer 1

We know that, electric field near a large charged sheet is given by
\(E = \dfrac{\sigma}{2 \epsilon_0} = \dfrac{Q}{2 A \epsilon_0}\)
As in the given problem, charge and dimensions of both sheets are the same, therefore charge density \((\sigma)\) is also same.
Hence, electric field will also be equal for both sheets.