VITEEE 2011 Paper

Here, net flux is zero, as there is no charge residing inside the cube.
Electric flux is given by electric field×area vector
area vector is a vector drawn perpendicular to a given surface area directed outside and magnitude is equal to the area.
In a uniform field, the intensity of field on any two opposite sides will be equal.
But the area vector will be equal and opposite. Hence the total flux will be zero.