The figure shows some of the electric field lines corresponding to an electric field. The figure suggests

Give characteristics of electric field lines.

The dimensional formula for electric flux is $..........$

Define electric flux.

Two point charges $8 \mu \text{C}$ and $-2 \mu \text{C}$ are located at $x = 2 \text{ cm}$ and $x = 4 \text{ cm}$, respectively on the $x$-axis. The ratio of electric flux due to these charges through two spheres of radii $3 \text{ cm}$ and $5 \text{ cm}$ with their centers at the origin is . . . . . . .

$A$ square Gaussian surface is placed in the $y-z$ plane. Its axis is along the $x-$axis and its center is at the origin. Two identical charges,each $Q$,are placed at points $(a, 0, 0)$ and $(-a, 0, 0)$. If each side length of the square is $2a$,then the electric flux passing through the square is: