Minimum number of $2\,\mu F$ and $250\, V$ capacitors required to make a combination of $12\,\mu F$ and $500\, V$ is:

In $Millikan's$ oil drop experiment,a charge $Q$ is held stationary between two plates under a potential difference of $2400\, V$. If a second drop with half the radius is to be held stationary using a potential difference of $600\, V$,then the charge on the second drop is:

If $n$ drops of the same size and same potential $V$ coalesce to form a single large drop,then the potential of the large drop will be .........

The diagram shows four capacitors with capacitances and breakdown voltages as mentioned. What should be the maximum value of the external emf source such that no capacitor breaks down? (in $kV$)

$A$ capacitor of unknown capacity is connected across a battery of $V$ volt. The charge stored in it is $Q$ coulomb. When the potential across the capacitor is reduced by $V_1$ volt,the charge stored in it becomes $Q_1$ coulomb. The potential $V$ is

The switch $S_w$ is shifted from position $1$ to position $2$ as shown in the figure. Heat generated in the circuit is