Note that the electric field is defined for a positive test charge \(q\), so that the field lines point away from a positive charge and toward a negative charge. (See Figure \(\PageIndex{2}\).) The el...Note that the electric field is defined for a positive test charge \(q\), so that the field lines point away from a positive charge and toward a negative charge. (See Figure \(\PageIndex{2}\).) The electric field strength is exactly proportional to the number of field lines per unit area, since the magnitude of the electric field for a point charge is \(E=k|Q| / r^{2}\) and area is proportional to \(r^{2}\).
Note that the electric field is defined for a positive test charge \(q\), so that the field lines point away from a positive charge and toward a negative charge. (See Figure \(\PageIndex{2}\).) The el...Note that the electric field is defined for a positive test charge \(q\), so that the field lines point away from a positive charge and toward a negative charge. (See Figure \(\PageIndex{2}\).) The electric field strength is exactly proportional to the number of field lines per unit area, since the magnitude of the electric field for a point charge is \(E=k|Q| / r^{2}\) and area is proportional to \(r^{2}\).
