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 $......\,kV$.

The potential of a large liquid drop formed when eight identical small liquid drops are combined is $20 \,V$. What was the potential of each single small drop (in $\,V$)?

The dimensions of electric potential are

Particles $A$ and $B$ have charges $+q$ and $+4q$ respectively. Both have the same mass $m$. If they are released from rest and accelerated through the same potential difference $V$,the ratio of their velocities $v_A/v_B$ is:

Two electric charges $12\,\mu C$ and $-6\,\mu C$ are placed $20\, cm$ apart in air. There will be a point $P$ on the line joining these charges and outside the region between them,at which the electric potential is zero. The distance of $P$ from the $-6\,\mu C$ charge is.......$m$.

Consider a sphere of radius $R$ having charge $q$ uniformly distributed inside it. At what minimum distance from its surface is the electric potential half of the electric potential at its centre?