Surfaces $A$ and $B$ are at the same potential $V'$. The work done in moving a charge $q$ from $A$ to $B$ is ........

Assertion: Two equipotential surfaces cannot cut each other.
Reason: Two equipotential surfaces are parallel to each other.

The nature of the equipotential surface for a point charge is:

The figure shows two equipotential lines in the $XY$ plane for an electric field. The scale is shown. The $X$-component $E_x$ and $Y$-component $E_y$ of the electric field in the space between the equipotential lines are respectively:

What is an equipotential surface? Draw equipotential surfaces for:
$(1)$ $A$ single point charge
$(2)$ $A$ dipole (charges $+q$ and $-q$ at a small distance)
$(3)$ Two $+q$ charges at a small distance
$(4)$ $A$ uniform electric field.

In the electric field of a point charge $+q$, a certain charge is carried from point $A$ to points $B, C, D$ and $E$ along the paths shown in the figure. Then the work done: