electric flux

Electric flud is the electric field lines cross a surface area, so it depends in a sense they are entering or leaving a surface area.

For a closed surface, i.e. a cube, a sphere, if the electric field lines are outwards, and they are coming from inside suggests that there must be a positive charge sitting inside so that these electric field lines start from it and come out of the surface. Such a flux is called positive electric flux. Similarly if the field lines enter the surface it is called negative electric flux.

Note that positive and negative are meant to indicate directions only and nature of charges.

Regards,

Team,

TopperLearning.