What is the total energy stored in a capacitor?

Lets us calculate the energy of the series combination first.

As we know that in series combination charge Q is constant. SO each capacitor will be carrying the same amount of charge.So total energy(u) in the combination will be :

= Q² / 2 [ 1/C₁ + 1/C₂ + 1/C₃ + ……..]
= Q²/ 2C₁ + Q²/2C₂ + Q² /2C₃ + ……..] ——2.16

So what we get is
U=U1+U2+U3+………
We know that when the capacitors are connected in parallel then the potential difference between each capacitor will be the same.
So the new equation for total energy will be :
U= C_pV²/2
= ½(C1+C2+C3+………)V²
½ (C₁V²+ C₂V²+ C₃V²+……………)

So at last equation formed is:
U=U1+U2+U3+…. ———-2.17

So the above result clarifies that the total amount of energy packed in set of condensors can be calculated by summation of all the energies stored in the individual capacitors of the circuit.