If there were only one type of charge of the universe then

Options

A. `oint_S vecE.dvecS ne 0` on any surface
B. `oint_S vecE.dvecS=0` if the charge is outside the surface
C. `oint_S vecE.dvecS` could not be defined
D. `oint_S vecE.dvecS=q/epsilon_0` if charges of magnitude q were inside the surface.

Answer

B, D

Explanation

It is not necessary that both types of charges should be there to apply Gauss.s theorem. For `oint vecE.dvecS` to be zero all charges must be outside the surface because there is only one type of charge. Similarly if some charge is there inside the surface then `oint vecE.dvecS =q/epsilon_0` .