Question

answer the question

Answer 1

Consider an electrostatic field line terminating at a point, say P. Enclose this point in a Gaussian surface. The field line is going into the surface and not coming out of it - there is net inward flux (considering the field directed towards P). According to Gauss theorem this means that the Gaussian surface must enclose a negative charge. This then means that the field line can terminate at P only when there is a negative charge at P. If there is no charge at P, the net flux through the Gaussian surface must be zero and the field line must emerge out of the surface. Thus an electrostatic field line can terminate only at a charge or it must continue to infinity