The magnitude of electric field intensity $E$ is such that, an electron placed in it would experience an electrical force equal to its weight is given by
$mge$
$\frac{{mg}}{e}$
$\frac{e}{{mg}}$
$\frac{{{e^2}}}{{{m^2}}}g$
A thin semi-circular ring ofradius $r$ has a positive charge $q$ distributed uniformly over it. The net field $\vec E$ at the centre $O$ is
A body of mass $M$ and charge $q$ is connected to a spring of spring constant $k$. It is oscillating along $x-$ direction about its equilibrium position, taken to be at $x = 0$, with an amplitude $A$. An electric field $E$ is applied along the $x-$ direction. Which of the following statements is correct?
Figure shows a rod ${AB}$, which is bent in a $120^{\circ}$ circular arc of radius $R$. A charge $(-Q)$ is uniformly distributed over rod ${AB}$. What is the electric field $\overrightarrow{{E}}$ at the centre of curvature ${O}$ ?
What is called electric field ?
The insulation property of air breaks down at $E = 3 \times {10^6}$ $volt\,/\,metre$. The maximum charge that can be given to a sphere of diameter $5\,m$ is approximately (in coulombs)