An electric field given by E→=4i^+3y2+2j^ pierces Gaussian cube of side 1 m placed at origin such that its three sides represents x, y and z axes. The net charge enclosed within the cube is

The x-component of electric field is constant and does not contribute to net flux through the closed surface. Due to y-component,Incoming flux= -6 units ( ∴ y = 0 )Outgoing flux= 9 units (∴ y = 1)By Gauss' law, ϕnet=qεo⇒9−6=qεoHence,   q=3εo