Two non-conducting spheres of radii $R_1$ and $R_2$ and carrying uniform volume charge densities $+\rho$ and $-\rho$, respectively, are placed such that they partially overlap, as shown in the figure. At all points in the overlapping region: $Image$

$(A)$ the electrostatic field is zero

$(B)$ the electrostatic potential is constant

$(C)$ the electrostatic field is constant in magnitude

$(D)$ the electrostatic field has same direction

Two charged conducting spheres of radii $a$ and $b$ are connected to each other by a conducting wire. The ratio of charges of the two spheres respectively is:

Three charged concentric nonconducting shells are given as shown in figure. Find the potential at point $A$

Write an equation for an electrostatic potential of a negative point charge. 

Which of the following statements is true about the flow of electrons in an electric circuit?

Two charges of magnitude $+ q$ and $-\,3q$ are placed $100\,cm$ apart. The distance from $+ q$ between the charges where the electrostatic potential is zero is.......$cm$