Electric field is given by $\overrightarrow{E}=\left(8\hat{\mathrm{i}}+4\hat{\mathrm{j}}+3\hat{\mathrm{k}}\right) \mathrm{N} {\mathrm{C}}^{-1}$. Electric flux through surfaces of area $100 {\mathrm{m}}^2$ layer in $X\mathit{-}Y$ plane, $Y-Z$ plane and $X-Z$ plane are in ratio

The arrangement is shown consists of three elements.
a. A thin rod of charge $-3.0 \mu \mathrm{C}$ that forms a full circle of radius $6.0 \mathrm{cm}.$
b. A second thin rod of charge $2.0 \mu \mathrm{C}$ that forms a circular arc of radius $4.0 \mathrm{cm}$ and concentric with the full circle, subtending an angle of $90°$ at the centre of the full circle.
c. An electric dipole with a dipole moment that is perpendicular to a radial line and has magnitude $1.28\times {10}^{-21} \mathrm{C} \mathrm{m}$
Find the net electric potential in volts at the centre.

Some equipotential surfaces, which are normal to $\mathrm{x}-\mathrm{y}$ plane are shown in the adjoining figure. The magnitude of the electric field is $(\mathrm{V} {\mathrm{cm}}^{-1})$ :