An infinitely long straight wire has a uniform linear charge density of 4 × 10^-9 C/m. The electric field at a distance of 0.2 m from the wire is approximately:

Field lines always point from positive to negative charge, are denser where the field is stronger, and never cross; an isolated positive charge has lines radiating symmetrically outward, while a dipole's lines curve from the positive to the negative charge.