For flash pictures, a photographer uses a capacitor of $30 \mu F$  and a charger that supplies $3\times {10}^3 \mathrm{V}$. Find the charge and energy expended in joule for each flash.

Three capacitors of capacitances  $10 \mathrm{\mu F},$  $20 \mathrm{\mu F}$  and $30 \mathrm{\mu F}$ are connected in parallel to a $100 \mathrm{V}$ battery as shown in Figure. Calculate the energy stored in the capacitors.

How many electrons must be added to one plate and removed from the other so as to store $25.0 J$ of energy in a $5.0 nF$ parallel plate capacitor? 

How would you modify this capacitor so that it can store $50.0 J$ of energy without changing the charge on its plates?

A battery of $10 V$ is Connected to a capacitor of capacity $0.1 F$. The battery is now removed and this capacitor is connected to a second uncharged capacitor. If the charge distributes equally on these two capacitors, find the total energy stored in the two capacitors. Further, compare this energy with the initial energy stored in the first capacitor.

Find the total energy stored in the capacitors in the network shown below.

A $10\mathrm{ }\mathrm{\mu F}$ capacitor is charged by a $30\mathrm{ }\mathrm{V}$ d.c. supply and then connected across an uncharged $50 \mathrm{\mu F}$ capacitor. Calculate the final potential difference across the combination.

A $10\mathrm{ }\mathrm{\mu F}$ capacitor is charged by a $30\mathrm{ }\mathrm{V}$ d.c. supply and then connected across an uncharged $50 \mathrm{\mu F}$ capacitor. Calculate the initial and final energies. How will you account for the difference in energy?

The net capacitance of three identical capacitors in of series is $1 \mu F$. What will be their net capacitance if connected in parallel?