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
$4Q$ and $16Q$ must be at the ends and $Q$ at a distance of $3$ $cm$ from the $16Q$.
$4Q$ and $16Q$ must be at the ends and $Q$ at a distance of $6 $ $cm$ from the $16Q.$
Electric field at the position of $Q$ is zero.
$B$ and $C$ both
There is a uniform spherically symmetric surface charge density at a distance $R_0$ from the origin. The charge distribution is initially at rest and starts expanding because of mutual repulsion. The figure that represents best the speed $V(R(t))$ of the distribution as a function of its instantaneous radius $R(t)$ is
Derive the formula for the electric potential energy of system of two charges.
A charge of $8\; mC$ is located at the origin. Calculate the work done in $J$ in taking a small charge of $-2 \times 10^{-9} \;C$ from a point $P (0,0,3\; cm )$ to a point $Q (0,4\; cm , 0),$ via a point $R (0,6\; cm , g \;cm )$
Two identical particles of mass m carry a charge $Q$ each. Initially one is at rest on a smooth horizontal plane and the other is projected along the plane directly towards first particle from a large distance with speed $v.$ The closest distance of approach be
How much kinetic energy will be gained by an $\alpha - $particle in going from a point at $70\,V$ to another point at $50\,V$