CBSE Class 12-science Answered

It is convenient to visualize an electrostatic field with the help of electric lines of force. For a given situation, the electric lines of force are drawn such that:

(a) the tangent to a line of force at any point gives the direction of the electric field intensity E at that point.

(b) the number of electric lines of force crossing a unit area, when area is held perpendicular to field lines, gives the magnitude of electric field at that point.

(c) they originate from positive charge(s) and terminate at negative charge(s).

(d) they do not form closed loops.

(e) they do not cross each other because at the point of intersection two tangents can be drawn so two directions of force is impossible at that point.

if) they are close together where the field is strong and far apart where the field is weak.

(g) they are parallel and equally spaced if the field is uniform.

(h) they cut equi-potential surfaces at right angles.