Gauss's law and Coulomb's law , although expressed in different forms , are equivalent ways of describing the relation between charge and electric field in static conditions . Gauss's law is epsilon_(0) phi = q_(encl) ,when q(encl) is the net charge inside an imaginary closed surface called Gaussian surface. The two equations hold only when the net charge is in vaccum or air . A Gaussian surface encloses two of the four positively charged particles. The particles that contribute to the electric field at a point P on the surface are

Which of the following are positively charged particles?

Figure shown a closed surfce which intersects a conducting sphere. If a positive charge is placed at the point P, the flux of the electric field through the closed surface