$27$ identical drops are charged at $22 \ V$ each. They combine to form a bigger drop. The potential of the bigger drop will be............ $V$.

The values of charges $q_1, q_2$ and $q_3$ as shown in the figure are:

What is the effective capacitance between points $X$ and $Y$ in the given circuit? (All capacitors are in $\mu F$)

$(a)$ $A$ $900 \; pF$ 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?

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:

The figure shows two identical parallel plate capacitors $A$ and $B$ of capacitances $C$ connected to a battery. The key $K$ is initially closed. The switch is now opened and the free spaces between the plates of the capacitors are filled with a dielectric of dielectric constant $K=3$. Then which of the following statement$(s)$ is/are true?