The electric field intensity at all points in space is given by $\overrightarrow{\mathrm{E}}=\sqrt{3}\hat{\mathrm{i}}-\hat{\mathrm{j}}$ volts/metre. The nature of equipotential lines in x-y plane is given by

The direction of uniform electric field E in .xy-plane is as shown in figure 1.

The equipotential lines will be perpendicular to electric field. Also electric field points from high potential region towards low potential region. Therefore nature of equipotential lines in x-y plane is given by figure 2.