A point charge is placed at the centre of spherical Gaussian surface. Is electric flux ϕE changed if (a) The sphere is replaced by a cube of same or different volume ? (b) The charge is moved off-centre in the original sphere, still remaining inside ? ( c ) The charge is moved just outside the original sphere ? (d) A second charge is placed near the outside to the origianl sphere ? (e) A second charge is placed inside the Gaussian surface ?