charge=1;
epsilon0=1;
e=1;
q=charge*e;
V[x_,y_]:=(q/(4Pi*epsilon0))/Sqrt[x^2+y^2];
DensityPlot[V[x,y],{x,-1,1},{y,-1,1},Mesh->10,MeshStyle->{Black,Dashed}]
ContourPlot[V[x,y],{x,-1,1},{y,-1,1},Mesh->10,MeshStyle->{Black,Dashed}]
Plot3D[V[x,y],{x,-1,1},{y,-1,1},Mesh->10,MeshStyle->{Black,Dashed}]