Four point charges $-1\mathrm{\mu C}, -2\mathrm{\mu C}, 3\mathrm{\mu C}$ and $\text{-2μC}$ are arranged on the four vertices of a square of side 1 cm. The dipole moment of this charge assembly is

$\overrightarrow{\mathrm{p}}=\sum {\mathrm{q}}_{\mathrm{i}}{\overrightarrow{\mathrm{r}}}_{\mathrm{i}}$

We can rearrange the charges to form three dipoles with charges as  (-2 and +2) ,(+1 and 1) and (-1 and +1) with first and third in opposite direction and second one is perpendicular to them.

$$\begin{gathered} \mathrm{q} = 1 \mathrm{\mu C} \\ \mathrm{P} = \left(1 \mathrm{\mu C}\right) \times 0.01 = 0.01 \mathrm{\mu Cm} \\ \mathrm{Net} \mathrm{dipole} \mathrm{moment}, \mathrm{Pnet} = \sqrt{2}\times 0.01 \mathrm{\mu Cm} = \sqrt{2}\times {10}^{-8} \mathrm{C}.\mathrm{m} \end{gathered}$$