At which point is the electric field maximum?

Draw an equipotential surface for an electric dipole.

$A$ point charge $+q$ is placed at the origin. The work done in moving another point charge $-Q$ along the straight line path $AB$ from point $A$ with coordinates $(0, a)$ to point $B$ with coordinates $(a, 0)$ is .......

The figure shows three points $A, B$ and $C$ in a uniform electric field $(\overrightarrow{E})$. The line $AB$ is perpendicular to $BC$ and $BC$ is parallel to $\overrightarrow{E}$. If $V_A, V_B$ and $V_C$ are the potentials at $A, B$ and $C$ respectively,then the correct option is

$A$ circle of radius $R$ is drawn with a charge $+q$ at the centre. $A$ charge $q_0$ is moved from point $B$ to $C$ along the circumference of the circle. The work done is:

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.