Two charges $+q$ and $-q$,each $1 \mu C$,are arranged as shown in the figure. If $x=2 \text{ cm}$ and $y=3 \text{ cm}$,then the potential difference $(V_A - V_B)$ is:

The potential difference $(V_A-V_B)$ in the arrangement shown in the figure is $(q=1 \mu C, x=2 \text{ cm}, y=3 \text{ cm})$.

Two point charges $q_1 = 4 \times 10^{-8} \ C$ and $q_2 = -6 \times 10^{-8} \ C$ are placed at points $A$ and $B$ respectively,which are $50 \ cm$ apart. At what distance from point $A$ on the line $AB$ is the electric potential zero (in $cm$)?

Which of the following graphs correctly shows how the electrostatic potential $V$ varies with distance $r$ from a point charge?

Two point charges of $1 \text{ nC}$ and $2 \text{ nC}$ are placed at two corners of an equilateral triangle of side $3 \text{ cm}$. The work done in bringing a charge of $3 \text{ nC}$ from infinity to the third corner of the triangle is . . . . . . $\mu\text{J}$. $( \frac{1}{4\pi\epsilon_{0}} = 9 \times 10^{9} \text{ N.m}^{2}/\text{C}^{2} )$

$A$ hollow metallic sphere of radius $R$ is given a charge $Q$. Then the potential at the centre is