$A$ particle of mass $0.2 \ gm$ and charge $1 \ \mu C$ is held at a distance of $1 \ m$ from a fixed charge of $1 \ \mu C$. If the particle is released,it will be repelled. The speed of the particle when it is at a distance of $10 \ m$ from the fixed charge is $.... \ m/s$.

Choose the correct statement for the given capacitor arrangement. (All the $6$ capacitors are of same capacitance)

$(a)$ $A$ $900 \; pF$ capacitor is charged by a $100 \; V$ battery [Figure $(a)$]. How much electrostatic energy is stored by the capacitor?
$(b)$ The capacitor is disconnected from the battery and connected to another $900 \; pF$ capacitor [Figure $(b)$]. What is the electrostatic energy stored by the system?

$A$ capacitor is made of two circular plates of radius $R$ each,separated by a distance $d \ll R$. The capacitor is connected to a constant voltage $V$. $A$ thin conducting disc of radius $r \ll R$ and thickness $t \ll r$ is placed at the center of the bottom plate. Find the minimum voltage required to lift the disc if the mass of the disc is $m$.

To establish an instantaneous current of $2\,A$ through a $1\,\mu F$ capacitor,the potential difference across the capacitor plates should be changed at the rate of:

In the given circuit, the ratio of charge stored in the capacitors $C, 2C, 3C, 4C, 5C$ is