In a regular hexagon each corner is at a distance 'r' from the centre. Identical charges of magnitude 'Q' are placed at 5 corners. The field at the centre is $\left(\mathrm{K}=\frac{1}{4\pi {ϵ}_0}\right)$

Given data: Identical charge of magnitude ‘Q’

Concept used: Electric fields

Detailed solution:

Since the charges 1 and 4, 2 and 5 are exactly opposite to each other the electric field due to them cancels each other. So, the electric field is only due to because of charge 3

$$\begin{gathered} E=\frac{1}{4\pi {\in }_0}\frac{Q}{r^2} \\ E=\frac{KQ}{r^2} \end{gathered}$$