The plates $S$ and $T$ of an uncharged parallel plate capacitor are connected across a battery. The battery is then disconnected and the charged plates are now connected in a system as shown in the figure. The system shown is in equilibrium. All the strings are insulating and massless. The magnitude of charge on one of the capacitor plates is: [Area of plates = $A$]

A charge of $Q$ coulomb is placed on a solid piece of metal of irregular shape. The charge will distribute itself

A simple pendulum of period $T$ has a metal bob which is negatively charged. If it is allowed to oscillate above a positively charged metal plate, its period will

Two identical metallic spheres $A$ and $B$ when placed at certain distance in air repel each other with a force of $F$. Another identical uncharged sphere $C$ is first placed in contact with $A$ and then in contact with $B$ and finally placed at midpoint between spheres $A$ and $B$. The force experienced by sphere $C$ will be.

Three point charges of magnitude $5 \mu C , 0.16 \mu C$ and $0.3 \mu C$ are located at the vertices $A , B , C$ of a right angled triangle whose sides are $AB =3\,cm$, $BC =3 \sqrt{2}\,cm$ and $CA =3\,cm$ and point $A$ is the right angle corner. Charge at point $A$ experiences

$N$ of electrostatic force due to the other two charges.

Four charges equal to $-Q$ are placed at the four corners of a square and a charge $q$ is at its centre. If the system is in equilibrium the value of $q$ is