Capacitors in Series

Let three capacitors C₁ , C₂ and C₃ be connected in series as shown. The capacitor plates are named A,B,C,D,E and F.

When a battery is connected to the series combination, the negative terminal of the battery supplies a –ve charge to plate F. Simultaneously, the positive terminal of the battery sucks negative charge from plate A and therefore creating a +ve charge on plate A. Thus, charge is conserved.So now plate A has a +ve charge and plate F has a –ve charge as shown.

Positive charge on plate A attracts electrons of the BC plate combination towards plate B. Therefore, a –ve charge and a +ve charge appears on plate B and plate C respectively as shown. The BC plate combination which is isolated from everything else remains neutral as a whole and only redistribution of charge takes place.

Similarly, electrons of the DE plate combination drift towards plate D , thus giving plate D a –ve charge and plate E a +ve charge as shown. Again, the DE plate combination as a whole remains neutral.

The above process continues till capacitors get fully charged.

You may have observed that any charge sent/sucked by the battery to /from the end plates i.e Plates A and F will induce an equal amount of charge in all the plates in between i.e in Plates B,C,D and E .

Therefore, in series combination of capacitors, each capacitor has equal charge for any value of capacitances.

As Q=CV for a capacitor

To summarise :-

All capacitors in series store equal charge for any value of capacitances.
Equivalent capacitance value is smaller than all the individual capacitance values.
Equivalent capacitance value is given by
As Q=same for all the capacitors connected in series therefore,