Which formula gives the energy stored in a charged capacitor?

$A$ parallel plate capacitor has a uniform electric field $E$ in the space between the plates. If the distance between the plates is $d$ and the area of each plate is $A,$ the energy stored in the capacitor is

Two capacitors,each of value $10 \ \mu F$,are connected in parallel and charged to $200 \ V \ DC$. What is the energy stored in the combination in Joules?

$A$ capacitor has two circular plates,each of radius $8\,cm$,separated by a distance of $1\,mm$. $A$ dielectric slab (dielectric constant $K = 6$) is inserted between the plates. Calculate the energy stored in the capacitor when it is connected to a $150\,V$ potential difference.

The energy required to charge a capacitor of $5\,\mu F$ by connecting a $d.c.$ source of $20\,kV$ is......$kJ$.

Two capacitors,one of capacity $\frac{C}{2}$ and the other of capacity $C$,are connected to a battery of voltage $V$ as shown. The work done in charging both the capacitors fully is