Define electric flux. Write its SI unit. Gauss’law in electrostatics is true for any closed surface, no matter what its shape or size is. Justify this statement with the help of a suitable example.
According to Gauss’ law in electrostatics, the surface integral of electrostatic field E produced by any source over any closed surface S enclosing a volume V in vacuum, i.e. total electric flux over the closed surface 5 in vacuum, is
Gauss’ law in electrostatics is true for a closed surface, no matter what its shape or size is.
So, in order to justify the above statement, suppose in isolated positive charge q is situated at the centre O of a sphere of radius r.
According to Coulomb’s law, electric field intensity at any point P on the surface of the sphere is