What is the direction of the lines of force at any point on the equipotential surface?

Two point charges of magnitude $+q$ and $-q$ are placed at $\left( -\frac{d}{2}, 0, 0 \right)$ and $\left( \frac{d}{2}, 0, 0 \right)$,respectively. Find the equation of the equipotential surface where the potential is zero.

$A$ uniform electric field of magnitude $100 \ V/m$ in space is directed along the line $y = 3 + x$. Find the potential difference between point $A(3, 1)$ and $B(1, 3)$ in Volts.

$A$ uniform electric field is directed along the $Y$-axis. Consider point $A$ as the origin $(0,0) \text{ m}$. The coordinates of point $B$ are $(0,2) \text{ m}$. The coordinates of point $C$ are $(2,0) \text{ m}$. If the electric potentials at points $A, B,$ and $C$ are $V_A, V_B,$ and $V_C$ respectively,which of the following options is correct?

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

The work done to move a charge on an equipotential surface is