Draw an equipotential surface of two identical positive charges for small distance.

Two charges $2 \;\mu\, C$ and $-2\; \mu \,C$ are placed at points $A$ and $B\;\; 6 \;cm$ apart.

$(a)$ Identify an equipotential surface of the system.

$(b)$ What is the direction of the electric field at every point on this surface?

A uniformly charged solid sphere of radius $R$ has potential $V_0$ (measured with respect to $\infty$) on its surface. For this sphere the equipotential surfaces with potentials $\frac{{3{V_0}}}{2},\;\frac{{5{V_0}}}{4},\;\frac{{3{V_0}}}{4}$ and $\frac{{{V_0}}}{4}$ have rasius $R_1,R_2,R_3$ and $R_4$ respectively. Then

Given below are two statements: one is labelled a

Assertion $(A)$ and the other is labelled as Reason$(R)$

$Assertion$ $(A)$ : Work done by electric field on moving a positive charge on an equipotential surface is always zero.

$Reason$ $(R)$ : Electric lines of forces are always perpendicular to equipotential surfaces.

In the light of the above statements, choose the most appropriate answer from the options given below 

The diagrams below show regions of equipotentials.A positive charge is moved from $A$ to $B$ in each diagram. 

Thepoints resembling equal potentials are