$A$ drop of $10^{-6} \ kg$ water carries $10^{-6} \ C$ charge. What electric field should be applied to balance its weight? (Assume $g = 10 \ m/s^2$)

Two equal and opposite charges of masses $m_{1}$ and $m_{2}$ are accelerated in a uniform electric field through the same distance. What is the ratio of their accelerations if the ratio of their masses is $\frac{m_{1}}{m_{2}}=0.5$?

The intensity of the electric field required to balance a proton of mass $1.7 \times 10^{-27} \ kg$ and charge $1.6 \times 10^{-19} \ C$ is nearly:

Two insulating plates are both uniformly charged in such a way that the potential difference between them is $V_2 - V_1 = 20\ V$ (i.e.,plate $2$ is at a higher potential). The plates are separated by $d = 0.1\ m$ and can be treated as infinitely large. An electron is released from rest on the inner surface of plate $1$. What is its speed when it hits plate $2$? $(e = 1.6 \times 10^{-19}\ C, m_e = 9.11 \times 10^{-31}\ kg)$

An electron is accelerated through a potential difference $(p.d.)$ of $45.5 \ V$. The velocity acquired by it is (in $m \ s^{-1}$)

An electron and a proton are placed in the same electric field. The ratio of their accelerations is ......