An electrostatic field line is a continuous curve. That is , a field line cannot have sudden breaks. Why not?
(b) Explain why two field lines never cross each other at any point.

Explanation

Electric field is continuous and exists at all points around a charges distribution. Hence an electrostatic field line is a continuous curve and cannot have sudden breaks.
(b) Two field lines never cross each other , because if they do so then at the point. Of intersection there will be two possible directions of electric field, which is impossible.