A point charge is placed at the centre of a spherical Gaussian surface. The flux fE is changed

(1) if the sphere is replaced by a cube of same volume
(2) if the charge is moved off centre of the sphere
(3) if the charge is moved outside the sphere
(4) if a second charge is placed inside the sphere

The correct statements are
(a)   1.2,3
(b)   1,3,4
(b)   1.2.4
(c)   3.4

Ans: D