Work done in moving a positive charge on an equipotential surface is

In the figure,the charge $Q$ is at the centre of the circle. Work done is maximum when another charge is taken from point $P$ to:

Equipotential surfaces are given as shown. The electric field intensity is ........

Positive and negative point charges of equal magnitude are kept at $(0, 0, a/2)$ and $(0, 0, -a/2)$,respectively. The work done by the electric field when another positive point charge is moved from $(-a, 0, 0)$ to $(0, a, 0)$ is

Draw an equipotential surface for a uniform electric field.

The figure shows a family of parallel equipotential surfaces and four paths along which an electron is made to move from one surface to another.
$(I)$ What is the direction of the electric field?
$(II)$ Rank the paths according to the magnitude of work done,greatest first.