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

The figure shows three points $A, B$ and $C$ in a region of uniform electric field $E$. The line $A B$ is perpendicular and $B C$ is parallel to the field lines. Then,which of the following holds good? ($V_{A}, V_{B}$ and $V_{C}$ represent the electric potential at points $A, B$ and $C$,respectively)

Assertion $(A)$: In a region of constant potential,the electric field is zero and there can be no charge inside the region.
Reason $(R)$: According to Gauss's law,the charge inside the region should be zero if the electric field is zero.

Three equal charges are placed at the corners of an equilateral triangle. Which of the graphs below correctly depicts the equally-spaced equipotential surfaces in the plane of the triangle? (All graphs have the same scale.)

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

There is a uniform electric field of intensity $E$ as shown in the figure. How many labelled points have the same electric potential as the fully shaded point?