$A$ metallic sphere is kept in between two oppositely charged plates. The most appropriate representation of the field lines is

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

Consider a region in free space bounded by the surfaces of an imaginary cube having sides of length $a$ as shown in the figure. $A$ charge $+Q$ is placed at the centre $O$ of the cube. $P$ is a point outside the cube such that the line $OP$ perpendicularly intersects the surface $ABCD$ at $R$, and $OR = RP = a/2$. $A$ charge $+Q$ is also placed at point $P$. What is the total electric flux through the five faces of the cube other than $ABCD$?

$A$ positive charge $q$ is placed at the centre of a neutral hollow cylindrical conducting shell with its cross-section as shown in the figure below. Which one of the following figures correctly indicates the induced charge distribution on the conductor? (Ignore edge effects)

What will be the total flux through the faces of the cube as shown in the figure with side of length $a$ if a charge $q$ is placed at:
$(a)$ $C$: centre of a face of the cube.
$(b)$ $D$: midpoint of $B$ and $C$.

Explain electric flux.