A line of an electric field er) it is a curve whose tangent vector is just e at every point in space, and it is normal to the equipotential surface everywhere The electric dipole Two charges Q andQ separated by a small distance s in space form an electric dipole. (see Fig 2-6) It generates a potential O ±r∈0b4m∈0a4丌∈0TbT Si Ince +(2+rs cos 8. aT(1+(2+2cos)12 r(1+5cos6)1 COS