The intensity of the electric field required to keep a water drop of radius $10^{-5} \, cm$ and carrying a charge of $1$ electron suspended in air is:

$A$ charged particle,initially at rest at $O$,follows the trajectory shown alongside when released. Such a trajectory is possible in the presence of:

$A$ charged particle (mass $m$ and charge $q$) moves along the $X$-axis with velocity $V_{0}$. When it passes through the origin,it enters a region having a uniform electric field $\overrightarrow{E} = -E \hat{j}$ which extends up to $x = d$. What is the equation of the path of the electron in the region $x > d$?

If an electron and an $\alpha$-particle are accelerated under a potential difference of $100 \, V$, what is the ratio of their momenta?

Three particles are projected in a uniform electric field with the same velocity perpendicular to the field,as shown in the figure. Which particle has the highest charge-to-mass ratio?

The electric potential varies in space according to the relation $V = 3x + 4y$. $A$ particle of mass $0.1 \, kg$ starts from rest from point $(2, 3.2)$ under the influence of this field. The charge on the particle is $+1 \, \mu C$. Assume $V$ and $(x, y)$ are in $S.I.$ units. The time taken to cross the $x$-axis is.....$s$