$100$ capacitors,each having a capacity of $10\,\mu F$,are connected in parallel and are charged by a potential difference of $100\,kV$. The energy stored in the capacitors and the cost of charging them,if electrical energy costs $108\;paise\;per\;kWh$,will be

The potential of point $A$ is greater than that of point $B$ by $19 \, V$. What is the potential difference in volts across the $3 \, \mu F$ capacitor?

For the circuit shown in the figure,the charge on the $4 \mu F$ capacitor is $....... \mu C$.

In the circuit shown below, $C_1 = 10 \, \mu F$, $C_2 = C_3 = 20 \, \mu F$, and $C_4 = 40 \, \mu F$. If the charge on $C_1$ is $20 \, \mu C$, then the potential difference between $X$ and $Y$ is ......... $V$.

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:

The space between the plates of a parallel plate capacitor of plate area $4 \ cm^2$ and separation $d = 1.77 \ mm$ is filled with uniform dielectric materials with dielectric constants $k_1 = 5$ and $k_2 = 3$ as shown in the figure. Another capacitor of capacitance $7.5 \ pF$ is connected in parallel with it. The effective capacitance of this combination is . . . . . . $pF$. (Given $\varepsilon_0 = 8.85 \times 10^{-12} \ F/m$)