The field lines around a system
of two positive charges (q, q) give a vivid pictorial
description of their mutual repulsion, while those around
the configuration of two equal and opposite charges
(q, –q), a dipole, show clearly the mutual attraction
between the charges The field lines follow some important
general properties:
(i)
Field lines start from positive charges and end at
negative charges If there is a single charge, they may
start or end at infinity (ii) In a charge-free region, electric field lines can be taken
to be continuous curves without any breaks