A bullet of mass $2\, gm$ is having a charge of $2\,\mu C$. Through what potential difference must it be accelerated, starting from rest, to acquire a speed of $10\,m/s$
$5\, kV$
$50\, kV$
$5\, V$
$50\, V$
When a negative charge is taken at a height from earth's surface, then its potential energy
Three point charges $Q, 4Q $ and $16Q $ are placed on a straight line $9$ $cm$ long. Charges are placed in such a way that the system has minimum potential energy. Then
Two identical thin rings each of radius $R$ meters are coaxially placed at a distance $R$ meters apart. If $Q_1$ coulomb and $Q_2$ coulomb are respectively the charges uniformly spread on the two rings, the work done in moving a charge $q$ from the centre of one ring to that of other is
Four charges are arranged at the corners of a square $ABCD$ of side $d$, as shown in Figure
$(a)$ Find the work required to put together this arrangement.
$(b)$ A charge $q_{0}$ is brought to the centre $E$ of the square, the four charges being held fixed at its corners. How much extra work is needed to do this?
Two positrons $(e^+)$ and two protons $(p)$ are kept on four corners of a square of side $a$ as shown in figure. The mass of proton is much larger than the mass of positron. Let $q$ denotes the charge on the proton as well as the positron then the kinetic energies of one of the positrons and one of the protons respectively after a very long time will be-