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-
$\frac{{{q^2}}}{{4\pi { \in _0}a}}\left( {1 + \frac{1}{{2\sqrt 2 }}} \right),\frac{{{q^2}}}{{4\pi { \in _0}a}}\left( {1 + \frac{1}{{2\sqrt 2 }}} \right)$
$\frac{{{q^2}}}{{2\pi { \in _0}a}},\frac{{{q^2}}}{{4\sqrt 2 \pi { \in _0}a}}$
$\frac{{{q^2}}}{{4\pi { \in _0}a}},\frac{{{q^2}}}{{4\pi { \in _0}a}}$
$\frac{{{q^2}}}{{2\pi { \in _0}a}}\left( {1 + \frac{1}{{4\sqrt 2 }}} \right),\frac{{{q^2}}}{{8\sqrt 2 \pi { \in _0}a}}$
Hydrogen ion and singly ionized helium atom are accelerated, from rest, through the same potential difference. The ratio of final speeds of hydrogen and helium ions is close to......
The work done to take an electron from rest where potential is $-60\, V$ to another point where potential is $-20\, V$ is given by.....$eV$
Charge $q_{2}$ is at the centre of a circular path with radius $r$. Work done in carrying charge $q_{1}$, once around this equipotential path, would be
Two charges $-q$ and $+q$ are located at points $(0,0,-a)$ and $(0,0, a)$ respectively.
$(a)$ What is the electrostatic potential at the points $(0,0, z)$ and $(x, y, 0) ?$
$(b)$ Obtain the dependence of potential on the distance $r$ of a point from the origin when $r / a\,>\,>\,1$
$(c)$ How much work is done in moving a small test charge from the point $(5,0,0)$ to $(-7,0,0)$ along the $x$ -axis? Does the answer change if the path of the test charge between the same points is not along the $x$ -axis?
The diagram shows a small bead of mass $m$ carrying charge $q$. The bead can freely move on the smooth fixed ring placed on a smooth horizontal plane. In the same plane a charge $+Q$ has also been fixed as shown. The potential atthe point $P$ due to $+Q$ is $V$. The velocity with which the bead should projected from the point $P$ so that it can complete a circle should be greater than