$A$ charge $q$ is placed at the center of a cubical box of side $a$ with the top open. The flux of the electric field through one of the five closed surfaces of the cubical box is:

Which statement$(s)$ among the following are incorrect:
$(i)$ $A$ negative test charge experiences a force opposite to the direction of the field.
$(ii)$ The tangent drawn to a line of force represents the direction of electric field.
$(iii)$ The electric field lines never intersect.
$(iv)$ The electric field lines form a closed loop.

The flux of the electric field $\overrightarrow{E} = 24 \hat{i} + 30 \hat{j} + 28 \hat{k} \text{ NC}^{-1}$ through an area of $20 \text{ m}^2$ on the $yz$ plane is

$A$ point source of $3000 \ lumen$ is located at the centre of a cube of side length $2 \ m$. The flux through one side is......$lumen$.

If the radius of the spherical Gaussian surface is increased,then the electric flux due to a point charge enclosed by the surface:

If the charges inside a sphere are $+2 \times 10^{-6} \ C$,$-5 \times 10^{-6} \ C$,$-3 \times 10^{-6} \ C$,and $+6 \times 10^{-6} \ C$,what is the total electric flux passing through the sphere?