14 shows the field lines around some simple
charge configurations As mentioned earlier, the field lines
are in 3-dimensional space, though the figure shows them
only in a plane The field lines of a single positive charge
are radially outward while those of a single negative
charge are radially inward 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