# Write some important characteristics of electric field lines

Important characteristics of electric field lines:
(i) A tangent to a field line gives the direction of

$$\begin{array}{l}overrightarrow{E}\end{array}$$
at that point. In fig
$$\begin{array}{l}overrightarrow{E_1}\end{array}$$
is electric field at P1 and
$$\begin{array}{l}overrightarrow{E_2}\end{array}$$
is a P2.
(ii) The direction in which a free unit positive charge moves is the positive direction of the electric field line.
(iii) The number of field lines linked with a unit area of cross-section is proportional to E.