$A$ point charge $Q$ is placed in a uniform electric field $\vec{E} = E_1 \hat{i} + E_2 \hat{j}$ at position $(a, b)$. Find the work done in moving it to position $(c, d)$.

Two metal plates having a potential difference of $800 \; V$ are $0.02 \; m$ apart horizontally. $A$ particle of mass $1.96 \times 10^{-15} \; kg$ is suspended in equilibrium between the plates. If $e$ is the elementary charge,then the charge on the particle is:

In the absence of gravity, a charge $q$ and mass $2m$ is placed stationary in a uniform electric field of intensity $E$. When the charge is released, its speed after $n$ seconds is . . . . . . .

$A$ block of mass $m$ containing a net negative charge $-q$ is placed on a frictionless horizontal table and is connected to a wall through an unstretched spring of spring constant $k$ as shown. If a horizontal electric field $E$ parallel to the spring is switched on,then the maximum compression of the spring is:

The acceleration of an electron in an electric field of magnitude $50\, V/cm$ is (given that the $e/m$ ratio of the electron is $1.76 \times 10^{11}\, C/kg$):

$A$ small block of mass $5 \, g$ and charge $5 \, \mu C$ is placed on an insulated, frictionless, inclined plane of angle $60^{\circ}$. An electric field is applied parallel to the inclined plane. If the block remains at rest, then the magnitude of the electric field is (Take $g = 10 \, m/s^2$):