Two point charges $\mathrm{q}_1(\sqrt{10} \mu \mathrm{C})$ and $\mathrm{q}_2(-25 \mu \mathrm{C})$ are placed on the x -axis at $\mathrm{x}=1 \mathrm{~m}$ and $\mathrm{x}=4 \mathrm{~m}$ respectively. The electric field (in $\mathrm{V} / \mathrm{m}$ ) at a point $\mathrm{y}=3 \mathrm{~m}$ on y -axis is, $\left[\right.$ take $\left.\frac{1}{4 \pi \varepsilon_0}=9 \times 10^9 \mathrm{Nm}^2 \mathrm{C}^{-2}\right]$