Two electrons are moving towards each other, each with a velocity of $10^6 \,m / s$. What will be closest distance of approach between them is ......... $m$

Three identical small electric dipoles are arranged parallel to each other at equal separation a as shown in the figure. Their total interaction energy is $U$. Now one of the end dipole is gradually reversed, how much work is done by the electric forces.

An electron enters in high potential region ${V_2}$ from lower potential region ${V_1}$ then its velocity

The escape speed of an electron launched from the surface of a glass sphere of diameter $1\ cm$ that has been charged to $10\ nC$ is $x \times 10^7\ m/sec$ . The value of $x$ is 

A charge of $5\,C$ is given a displacement of $0.5\,m$. The work done in the process is $10\,J$. The potential difference between the two points will be.......$V$

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 $R (0,6\; cm , g \;cm )$