$A$ metallic solid sphere is placed in a uniform electric field. The lines of force follow the path$(s)$ shown in the figure as:

$A$ Gaussian surface of radius $R$ encloses a charge $Q$. If the radius is doubled,the outward electric flux will...

Define electric flux.

Assertion: Four point charges $q_1, q_2, q_3$ and $q_4$ are as shown in the figure. The flux over the shown Gaussian surface depends only on charges $q_1$ and $q_2$.
Reason: Electric field at all points on the Gaussian surface depends only on charges $q_1$ and $q_2$.

Select the correct statement regarding electric field lines.

$A$ 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: