An electric charge $10^{-3} \mu C$ is placed at the origin of $x-y$ plane. The potential difference between points $A$ and $B$ located at $(\sqrt{2} m, \sqrt{2} m)$ and $(2 m, 0 m)$ respectively is (in $V$)

Electric potential at a point distant $0.5 \,m$ from a spherical conductor of radius $0.2 \,m$ charged to $+1 \,nC$ is

$A$ thin metallic disc is rotating with constant angular velocity about a vertical axis that is perpendicular to its plane and passes through its centre. The rotation causes the free electrons in the disc to redistribute. Assume that there is no external electric or magnetic field. Then,

$A$ regular hexagon of side $5 \, cm$ has a charge $10 \, \mu C$ at each of its vertices. The potential at the centre of the hexagon is

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 $cm$)?

An infinite number of charges,each equal to $0.2\,\mu C$,are arranged in a line at distances $1\,m, 2\,m, 4\,m, 8\,m, \dots$ from a fixed point. The potential at the fixed point is $......\,kV$.