The maximum electric field that can be held in air without producing ionisation of air is $10^7\,V/m$. The maximum potential therefore, to which a conducting sphere of radius $0.10\,m$ can be charged in air is

An electron enters between two horizontal plates separated by $2\,mm$ and having a potential difference of $1000\,V$. The force on electron is

Two parallel plates separated by a distance of $5\,mm$ are kept at a potential difference of $50\,V.$ A particle of mass ${10^{ – 15}}\,kg$ and charge ${10^{ – 11}}\,C$ enters in it with a velocity ${10^7}\,m/s.$ The acceleration of the particle will be

Variation of electrostatic potential along $x$-direction is shown in the graph. The correct statement about electric field is

The potential $V$ is varying with $x$ and $y$ as $V\, = \,\frac{1}{2}\,\left( {{y^2} – 4x} \right)\,volt.$ The field at ($1\,m, 1\,m$ ) is