The figure shows a family of parallel equipotential surfaces and four paths along which an electron is made to move from one surface to another as shown in the figur
$(I)$ What is the direction of the electric field ?
$(II)$ Rank the paths according to magnitude of work done, greatest first

Three point charges $q, q$ and $-2 q$ are placed at the corners of an equilateral triangle of side '$L$'. Calculate work done by extemal force in moving all the charges far apart without acceleration

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 ......... $m$

Two point charges $100\,\mu \,C$ and $5\,\mu \,C$ are placed at points $A$ and $B$ respectively with $AB = 40\,cm$. The work done by external force in displacing the charge $5\,\mu \,C$ from $B$ to $C$, where $BC = 30\,cm$, angle $ABC = \frac{\pi }{2}$ and $\frac{1}{{4\pi {\varepsilon _0}}} = 9 \times {10^9}\,N{m^2}/{C^2}$.........$J$

For equal point charges $Q$ each are placed in the $xy$ plane at $(0, 2), (4, 2), (4, -2)$ and $(0, -2)$. The work required to put a fifth change $Q$ at the origin of the coordinate system will be

Define electron Volt and convert it into Joule unit.